Where can the earth's expanding pop- most practical solutions to the problem. Westinghouse is prepared to sta ulation get the fresh water it needs? Since 1951, 57 Westinghouse de- building water-desalting facilities to We can get it from the endless supply salting units have been installed around help solve water deficiencies for coastal in the sea. the world. They are desalting millions cities of any size—anywhere in the Desalting plants offer one of the of gallons of water a day. world. the companies making the same promises, how do you tell the difference? It is difficult! Perhaps the best and only way is to study the com- s!gn of spaceborne electronic and optical systems...plus pany carefully-to see if its structure, range and operational worldwide engineering support systems. modes permit it to make good its promises. If you scrutinize Note that SES has worked out three distinct routes for ad- Sylvania Electronic Systems, you'll discover a number of sal- vancement, all with equal rewards—technical specialist, tech- ient facts that may help clarify the matter for you. nical manager, program/project manager. Note first that Sylvania employs the small group form of or- Finally, note how SES encourages ambitious individuals to ganization—within its nationwide complex of research and de- accelerate their development through participation in Division- velopment groups, manufacturing plants and world-wide field wide conferences, in-plant courses and seminars and post- engineenng operation. This makes swift individual progress graduate study plans conducted on an unusually generous and development possible within a wide choice of current in- scale. house projects. The success of the SES mission—to manage government Note particularly the diversity and breadth of SES projects. systems programs for General Telephone & Electronics, the you may advance in a technical or administrative capacity in parent corporation—depends on the professional and intellec- any of t h e s e are as: ground electronics equipment for Minute- tual growth of its personnel. In every respect, SES has created man missile sites...research and development in electronic an environment to foster that growth. Be sure that any prospec- warfare field...electronic security systems... tive employer you consider has established a ASW systems...special purpose airborne com- growth climate of like specifications. puters for incorporation into U.S. Air Force large Making promises is one thing. Making progress scale ele is another. ctronic systems... laser systems... de- How soon after graduation will somebody give you a chance to invent something? It could happen on your first job. Some very young engineers and scientists at appear, they don't yet fully reveal the true technology Xerox helped our "old timers" invent the electro- Xerox is pursuing—graphic communications. mechanical-optical-chemical machine pictured above Born out of the global information explosion —the Xerox 2400. On its patent documents you'll find and its incredible potential for helping to solve mans names like John Wirley (BSEE Univ. of Detroit '60), oldest problems (as well as his newest scientific rid- Henry P. Jankowski (BSEE Rensselaer Poly '62), and dles), graphic communications at Xerox encompasses Larry H. Warren (BSEE Clarkson '63). They all joined the entire spectrum of communications in a graphic Xerox right after graduating. sense: the formulation, reception, transmission, re- The 2400 is no fluke. It's just a recent example cording, storing, retrieving, processing, copying and of a tradition that began in 1959, when Xerox revo- presentation of any meaningful images. lutionized the office copying field by introducing the And if you don't think all this has a habit or now world-famous 914 Copier. From the 914 onward, creating continuing opportunities to "invent some- every new piece of equipment or system we've devel- thing," ask John, Henry, Larry . . . or some of you oped has had no real counterpart already on the scene own alumni who started their careers here...or your from any competitor. Placement Director. If you prefer, write directly to What about the future? It gets even more inter- Mr. Stephen G. Crawford, Xerox Corporation, P.O esting. Because as advanced as today's systems may Box 1540, Rochester, New York 14603. FRED GEORGE editor ARTICLES TOMMcCLURE, artist ON PLANETARY LANDINGS BY SPACECRAFT T. Heppenheimer 18 staff MEASURING THE GASOLINE JOE BOWMAN RATING SEVERITY OF TEST SUSAN GOODSELL AUTOMOBILES BRIAN GOLUSKA T. A. Hewett 28 GARY ROMANS RICHARD MARETT GEARS BETWEEN THE EARS Dr. Paul Grogan 34 advisors j . RYDER DEPARTMENTS C. MENSENDICK Editorial 6 T. FARRELL Placement Bureau 8 G. VANDUSEN Industrial Spotlight '2 Industrial News 38 Index To Advertisers 51 He was a great scientist in his day This Sumerian was mindingour busi- is a major reason TB deaths de- ness five thousand years ago. To take a big sting out of life, Olin is creased 60% in the last eight years. developing a high speed cartridge that Like Olin, he specialized in chemi- Olin's ammonium phosphate fertiliz- cals and metals. He smelted copperand enables medicine to be injected without er (Ammo-Phos®) makes it possible for the use of hypodermics. tin to make bronze. He made an iron farmers to grow more food than ever But none of these advances could axle, put it between two wheels, and off before. have been made without our scientists. he went. And to prevent the tremendous Every division of Olin seeks the cre- Men have always been trying to find waste in food spoilage, we're working on the answers to important problems.To- ative, scientific mind for the answers to an antibiotic-coated plastic wrapping. the research problems of our day. If this day, Olin is at it, harder than ever. Our pioneering research in liquid is the kind of work that interests you, chlorine helped eradicate typhoid and call Olin or write to M. H. Jacoby, Col- other water-borne diseases. lege Relations Officer, Olin Mathieson Chemical Corporation, 460 Park Ave- Our anti-tubercular drug, NYDRAZID® nue, New York 22, N.Y. We're sending some of our representatives back to school They won't be matriculating but The NASA Gemini has set new re- they'll be studying ways to have cords in space, laying the ground- some lengthy talks with you. work for exploration of the moon and Their assignment is to search out it is being readied for new assign- graduates who have the talent and ments with the Air Force. imagination to handle sophisticated If these projects strike sparks with assignments and the determination your imagination you're in good to do a job better than most. company... the top scientific and en- The vitality of McDonnell is ap- gineering talents in the nation. parent by the headline-making strides it has taken in spacecraft, air- For more information see your craft, electronics and automation. College Placement Office What about the People on the Curb? I don't understand people. Maybe it's because I'm only 19 years old, or may- be it's because I'm an engineer. I just don't understand people at all. A campus bus seats 53 people, with standing room for 50 or 60 more. I got on a bus today, across from the Brody complex. When the bus left, 15 people were left standing at the curb in the cold to wait for the next bus. Yet there would have been room for 20 more people if those on the bus had moved to the back and filled in the empty spaces between them. Despite three requests by the bus driver, those standing in the aisles would not move back fully, but continued j to leave unnecessary empty space. They left 15 people standing in the snow on the curb. Why will people force others to stand in the cold, when moving three or four feet would prevent it? Why do their egos require a space four or five times the size of the space their bodies require? Are they afraid that someone will actually bump against them (horrors) when the bus turns a corner? Could it be that these people aren't even aware of the discomfort of those who are being forced to wait for another bus? Furthermore, these " m a t u r e " people grumble if asked to move as far back as possible. Is it unjustified for the bus driver to try to carry as many people as he can? I watched a girl stand in the middle of the aisle, with six feet of unused space behind her, inaccessible to those wishing to board the bus. Five or six people could stand in that area, six feet long and three feet wide, but she stood there expressionless while the driver asked twice for people to move back. The third time the driver asked, she scowled and moved back a foot and a half Why, when a student responds to the bus driver's plea by saying, "C'mon, let's move back and make room," does he receive dirty looks and not even half-hearted cooperation? Why don't people have any consideration for others? I don't understand at all. Needed: bearings that can turn at 50,000 rpm. higher speeds? At SKF, we're re- U.S.A. Applications range from space- These scale models are used in wind- craft to construction machinery. And tunnel tests for the Mach 3 SST super- searching for this now. And for bear- sonic transport. SKF Industries, Inc. ings that can operate at 1,000°F. Or tomorrow? Wherever progress calls is prime contractor for bear- under pressures of tons per square for new advances in Motion Research ings in this fascinating project. inch in the hydrospace. and Engineering —you'll find SKF® After that, what? Even f a s t e r aircraft, SKF makes every type of rolling bear- bearings. Write for our brochure, calling for bearings capable of even ing—the most complete line in the Form No. 515, to Dept. 889-00. PLACEMENT BUREAU (Note: This is only a list of January 18 January 25 those employers scheduled to Alleghany Ballistics Laboratory Abbot Labs visit MSU as of January first. Ex-Cel-0 Corp. Applied Physics Laboratory This does not mean that ad- Interlakes Steel Corp. DuPont ditional employers will not come Leeds & Northrup Co. Fairbanks Morse to MSU on a given date, or that Ohio Edison Co. General Tire & Rubber the employers listed here will Penn Salt Chemical Co. Upjohn not add to or revise their sched- Raytheon Corp. uled visits.) West Virginia Pulp and Paper U.S. Geological Survey January 26 Boeing DuPont January 12 Reynolds Metals Marshall Space Flight Corp. January 19 Union Carbide National Electric Welding Alleghany Ballistics Laboratory National Home Corp. B F Goodrich Peerless Division of the Ameri- Bulldog Electric Division of January 27 can Cement Corp. I.T.E. Boeing Pitt. Plate Glass Congall Corp. John Deere and Co. Sealright Corp. Esso Research Reynolds Metals Interlake Steel Corp. Swift & Co. I Raytheon Corp. Union Carbide January 13 Union Carbide Carnation U.S. Atomic Energy Cities Service Oil Co. Xerox Corp. January 28 Illinois Bell Telephone Boeing Packaging Corp. of America Desoto Chemical Coatings U.S. Corrugated Fiberbox Co. January 20 General Telephone and Electric E. W. Bliss Hamiliton Standard Division of Vick Chemical Co. United Aircraft January 14 Sealed Power Ansul Co. Whirlpool January 31 Carnation Lear Siegler Cities Service Oil Co. Lockheed -California Food Machinery Corp. January 21 March & Co. * Naval Ordinance Laboratory Giffels & Rossetti Consulting Co. North American Aviation Morse Chain Co, Hamilton Standard Division of U.S. Department of Public Health Pock Corp. of America United Aircraft U.S. Naval Ordinance Test Center U.S. Rubber Northrup Corp. Whirlpool General Motors Wyandotte Chemical Co. February 1 January 17 General Motors Abitibi Corp, North American Aviation January 24 Hercules Powder Co. Continental Can Co. Abbot Labs Heath Survey Consultants Jones & Laughlin Steel Applied Physics Laboratory Minnesota Mining & Manufac- McLouth Steel Federal Mogul Corp. SylvaniaElectric System turing U.S. Naval Missile Center Socony Mobil Where will YOU stand 10 years from today, when half of what you now know becomes obsolete? Right now you're steeped in the latest we've found it's the best way for Your first opportunity with IBM starts technologies. But 10 years from now IBM to grow. with your placement officer. And with half of this knowledge will be obsolete. the IBM interviewers when they come ANdhalfof what you will need to know Today IBM is a leader in science to your campus. See them—and learn isn't even available today. and technology. A dynamic company why you won't stand still at IBM. whose people and systems are at To keep up, you'll have to spend work on almost everything new in the For more information, or if an increasing amount of your time in world today. The discovery of new you missed our interviewers, write to: Professional study. knowledge. The design of new Manager of College Relations products. The development of new IBM Corporate Headquarters That's another good reason for joining solutions to a host of problems. IBM Armonk, New York 10504 IBM. We offer you a broad choice of is an exciting company that enables you to stay technologically "hot" IBM is an Equal Opportunity Employer. educational programs-from on-job throughout your career—and provides you with real opportunity for training to graduate study programs advancement. supportedbythe company. We want to help you grow because February 2 February 15 February 28 Radio Corp. of America Bendix Shell Oil General Mills General Dynamics Kodak Cummins Engine Fischer Governor New Holland Square D Burrows Rex Chain Belt General Motors McDonald Aircraft Sylvania Electric Systems March 1 February 3 Owens-Illinois Radio Corp. of America February 16 Hughes Aircraft General Mills Olin Inland Container Corp. General Motors McDonald Aircraft Ameco Chem. Co. Bell Telephone Power Controls-Midland Ross U.S. Army Corp of Engineers Cornell Aeronautical Lab. U.S. Army Tank Automotive Alleghany Ludlum Steel Corp. Center West Virginia Pulp & Paper March 2 Ownes-Illinois February 4 Falk Corp. Anchor-Hocking February 17 Industrial Nucleonics Gulf Research &. Development Motorola Humble Oil Scott Paper Douglas Aircraft Proctor & Gamble General Motors International Milling Honeywell Inc. Firestone Tire & Rubber March 3 Collins Radio Co. February 7 February 18 Proctor & Gamble General Electric Douglas Aircraft Kellogg Co. Dow Corning Firestone Tire & Rubber U.S. Gypsum J. I. Case KVP-Sutherland B. F. Goodrich Owen-Ames-Kimball Ohio Dept. of Highways NASA Grummend Aircraft February 8 March 4 General Electric February 21 Collins Radio Co. U.S. Steel Caterpillar Tractor Co. NASA Rockwell Standard The Martin Co. Dura Corp. Nalco Chemical Co. Texaco Washington State Highway Babcock & Wilcox Glidden Co. Commission Miles Lab. February 22 February 9 Caterpillar Tractor Co. March 7 Standard Oil The Martin Co. Sperry Phoenix International Harvester Ford Miss. Valley Structural Steel Co. Kimberly-Clark Texas Instruments Navy-Marine Engineering Goss Co. Goodyear Atomic Bell Arrow Systems March 8 February 23 Surface Combustion Ford Libbey-Owens-Ford February 10 The Martin Co. Westinghouse Elec. Standard Oil Texas Instruments Air Force Logistics Command Kimberly-Clark General Foods Alcoa Control Data Crop. Indiana & Michigan Elec. Co. I.B.M. March 9 Interstate Elec. February 24 M. W. Kellogg February 11 U.S. Army Material Command I.B.M. Inland Steel Allis-Chalmers Pfizer & Co. Sundstrand Corp. March 10 Hewlett-Packard Co. Magnavox Continental Oil Youngstown Sheet & Tube Interstate Minerals & Chemical Worthington Corp. February 14 February 25 U.S. Rubber Pan-American Petroleum Sinclair Bendix Weyerhauser March 11 General Dynamics Standard Oil Interstate Minerals & Chemical Factory Mutual Engineering Div. California State (Personnel Hyster Co. Board) Aeroneutronics Arm yourself w i t h facts about DuPont These booklets helped influence some 863 new technical gradu- ates of all degree levels to join us in 1964. For example, if you want to start your career in a certain section of the country, you'll find that Du P o n t - w i t h facilities in 28 s t a t e s - w i l l try to accommodate you. If you're interested in growth for what it can mean to you personally, you'll be interested to know that our sales have increased more than 750% since 1937. You've probably heard that R&D expenditures are a good indicator of a company's future success. We spend $90 million a year on it, $60 million of which goes straight into "pioneering research"-the discovery of new sci entific truths and new materials. Our booklets will answer most of your preliminary questions. Later-or even now if you wish-we can talk specifics by letter, or face to face. Why not write us or send our coupon? We'd like to know about you. SCOTT INDUSTRIES, INC. One of the major problems fac- contained unit (70 inches high, SCOTT ANALOG-FLUID CIR- ing the engineering programs of 130 i n c h e s wide and 33-1/2 CUIT-Model 9012: Bench-sized many universities today is the inches deep) delivers horizontal unit is electrically analagous to expense and space availability of laminar air flows at velocities flow conditions that develop in conducting regular programs of from 15 to 110 feet/second to 6- piping circuitry under various s t u d e n t experimentation. This inch square transparent plastic input conditions. problem is being eased greatly test section capable of open or Plug-in modules simulate var- by the Scott Professional De- enclosed operation. It can also ious sizes of numerous types of velopment System for Engineer- deliver up to 15 feet/second pos- commercial valves, fittings and ing Education, a division of Scott itive or negative direction ver- pipes. Voltage simulates pres- Industries, Inc. tical laminar air flows to 18 sure drop t h r o u g h system or I inch open test sections. Vane- component. Current simulates S c o t t Professional Develop- axial blower speed is infinitely flow. Inputs are manipulated by ment Systems (18 in all and variable between 438 and 1750 master control to electrically more planned) are small, usually rpm. CONTINUED TO PAGE 14 bench-sized or portable, pieces of apparatus. They Incorporate, either integrally or as accessory equipment, everything needed to interest engineering students in setting up and observing exper- iments, in various fields of en- gineering. Scott Systems are used in Senior and Junior Colleges throughout the country. Currently many are also finding their way into Vocational s c h o o l s , into Adult Education, and into First- Class Technical High School Pro- grams. Recently five new or improved Systems for Engineering Educa- tion have been announced to the educational systems market. Career on Your mind? Think Future. Think Celanese. If you're ambitious, flexible, Financial Reward. We know of no other company better andi m a g i n a t i v e - a n dif you're well trained in chemistry, able, or more disposed, to satisfy these needs. Working with chemical and mechanical engineering, physics, marketingCelanese, you'll have the chance to grow and broaden or accounting-you'reour man. quickly. Why Celanese? You'll be working for a company that's grow- Sound good? If you feel you can perform in our demanding ing fast-and "Plans" to keep growing. 1964 sales rose environment, it should. Discuss us with your faculty and Placement Office now, then plan to see our representative more than2 5 % t 0 ° V e r $ 7 0 ° m i l l i o n - O u r f u t u r e " P | a n n e d " when he is on your campus. Or write to: Matthew Park, Jr., growth depends on o u r ability to attract top-notch people Supervisor of University Recruitment, Celanese Corporation who have the drive and desire to aim for that second billion. of America, 522 Fifth Avenue, New York, what makes y o u t i c k ? Responsibility. Auth °rity. Professional Recognition, New York, 10036. AN EQUAL OPPOR attained with use of high vel- ocity air-jets to drive fan and operate motor as a generator, Instrumentation i n c l u d e s pitot tube with manometer, load cell with manometer, venturi with pressure gages, voltmeter and ammeter. SCOTT FORCE and MOMENT I N D I C A T O R SYSTEM-Model 9032: System provides precise determination of forces and mo- ments resulting in lift, drag, roll, pitch and yaw when aerodynamic shapes are mounted on thin col- umn in air streams of various types. Comparison of aerody- namic behavior of various mode! s h a p e s and demonstration of floating shafts is also possible. This bench-sized unit utilizes virtually friction-less air-sup- ported shafts and can be null set. Accordingly measurements are obtained by manometers con- nected to load cells and cali- brated to read to high accuracy directly in force units. d u p l i c a t e hydraulic situations. rather than a dc source so that Immediately readable measure- drift problem is eliminated. Unit Each Scott System is designed ments summarize the complex is fully silicon transistorized for specifically for its task of in- calculations of incompressible reliable operation and long life. ducing original student research fluid flow (current) through an P o s i t i v e burn-out protection as well as demonstrating funda- entire simulated piping system, makes unit electrically student- mental laws in classical areas thus elimating need for indivi- proof. It is intended for use with of the engineering curricula...the dual calculations which can be- standard bonded resistance wire b e h a v i o r of structures under come tedious as components are strain gages and complements stress (Scott Structures TestSy- added. other Scott units designed to load- stem-Model 9004), the properties test materials and structures. of m a t e r i a l s (Scott Materials SCOTT STRAIN INDICATOR Test System-Model 9014), fluid S Y S T E M - M o d e l 9083: This SCOTT TURBOFAN SYSTEM- flow characteristics (Scott Fluid benchtop, cabinet unit is designed Model 9005: This bench-top unit Circuit System-Model 9009 and as an economic means of intro- enables student determination of Analog-Model 9012), thermody- ducing the student to strain gage l a m i n a r versus turbulent flow namics (Scott Double Pipe Heat investigation of stresses and properties, pressure and vele- E x c h a n g e r s - M o d e l s 9052 and strains in materials. Accuracy is ocity relationships, turbine blade 9052B; R a d i a t i o n and Temp- 3% of full scale (10,000 mic- properties, aerodynamic princi- ature Measurement System-Mo- roinches per inch). Current is ples, manometer usage, many del 9053) are only a few in Scott's fed to the bridge from an ac more. Dynamometer effects are CONTINUED TO PAGE30 Tod ay, U.S. Rubber is involved in many fields includingatomic research, oceanography and space research. One o f o u r representatives will be visiting your school soon. Check with your placement office for the exact date and time. Ford Motor Company is: stimulation What does it take to "spark" a man to his very best . . . to bring out the fullest expression of his ability and training? At Ford Motor Company we are convinced that an invigorating business and professional climate is one essential. A prime ingredient of this climate is the stimulation that comes from working with the top people in a field . . . such as Dr. James Mercereau. Jim Mercereau joined our Scientific Laboratory in 1962. Recently, he headed a team of physicists who verified aspects of the Quantum Theory by creating a giant, observable quantum effect in superconductors. This outstanding achievement was the major reason the U. S. Junior Chamber of Commerce selected Dr. Mercereau as one of "America's Ten Outstanding Young Men of 1964.' Your area of interest may be far different from Dr. Mercereau's; however, you will come in contact with outstanding men in all fields at Ford Motor Company. We believe the coupling of top experience and talent with youth and enthusiasm is stimulating to all concerned. College graduates who join Ford Motor Company find themselves very much a part of this kind of team. If you are interested in a career that provides the stimulation of working with the best, see our representative when he visits your campus. We think you'll be impressed by the things he can tell you about working at Ford Motor Company. Engineering and Science at RCA Integrated Launch Control ing to expand in factory and italic testing,as Traveling Wave Masers well as launch operations, as automation tech and Checkout Systems niques are applied to other Saturn subsystems. RCA's recent maser research and development for Saturn Lunar Vehicles has yielded systems with outstanding low-noise microwave amplifier performance along with Highly sophisticated Saturn automatic ground adaptability for field use. These amplifiers ex- checkout and launch sequencing equipment hibit ultra-low noise temperature (8-10°K) and has been under development by RCA since high gain (30-40 db) with extreme gain sta- late 1960 for the National Aeronautics and A Light Detector That Makes bility. Wide tunability (up to 50%) and large Space Administration, Marshall Space Flight instantaneous bandwidth (up to 150 MHz) Center. The original Saturn Ground Computer Laser Communications Practical have been achieved. System (SGCS) was used on the highly suc- cessful Saturn I program: an advanced version RCA has developed a photoconductive device Several technique areas involved with this of the SGCS is currently being readied for the that operates on an alternating currcnl that work are of particular interest. Iron- and Saturn IB and Saturn V programs. The RCA can sense up to 100 million changes in light chromium-doped rutile (titanium dioxide) are 110 computer was the heart of the Saturn I intensity per second. This is sufficient to dis- employed as active paramagnetic materials, in SGCS: the RCA I10A is the heart of the tinguish as many as 25 separate television a "meander-line" slow wave structure, provid- Saturn IB and Saturn V SGCS. programs, all carried on a single laser beam. ing wide bandwidth and high gain. Ferrite re- This major breakthrough in lighl detection is verse isolators function to provide a high extremely fast, enormously sensitive and is degree of gain unidirectionality. The requisite responsive to the whole range of optical fre- magnetic field is provided by a superconduct- quencies, ranging from infra-red through the ing magnet within a cryogenic enclosure, and visible spectrum to ultra-violet. the entire system is operated by a closed-cycle By contrast, previous means of detecting refrigerator requiring no helium replenishment, laser light employed photoconductors operated so that field use in radar systems, satellite com- by direct current, photoelectric cells, semicon- munications and radiometry is practical. Sec- ductor photodiodes and electron pholomulti- tionalized magnet structures with independent plier tubes. The major drawbacks were that controls permit "stagger-tuning" the maser, these methods were cither too slow, loo in- so that its very high gain can be traded for sensitive, or too limited to the portions of the even greater bandwidth. electromagnetic spectrum where most lasers operate poorly, if indeed, at all. The laser is, to state it simply, a high fre- quency transmitter with the capacity to carry a fantastic amount of information. The real problem has been to develop a receiver both The block diagram shows the tandem, two fast enough and sensitive enough to detect and computer configuration for Saturn V at Com- process incoming information. This new device plex 39, the lunar program "space port" at has the sensitivity, speed and frequency range NASA's Kennedy Space Center. Complex 39 that can make possible a practical system for is based on a mobile launch concept to gain laser communications. high efficiency in launch operations. Vehicles are assembled in the Vehicle Assembly Build- This radical new detector is a tiny speck- ing (VAB) on a Mobile Launcher structure. sized piece of photoconductive material After the Saturn V with its Apollo Spacecraft mounted in a small cavity continuously bathed is completely checked out, the vehicle in its in microwaves oscillating at 10 billion cycles The illustration shows the active elements Launcher is transported to one of three launch per second. of a maser amplifier typical of such a high- pads for a remotely controlled launch. The computer in the Launch Control Center (LCC) When a laser beam bearing information in pcrformance system. The meander line, seen the form of intensity variations enters the as a zig-zag conducting path on a flexible in- controls the activities of the "slave" computer in the Mobile Launcher via a 250 kilobit/sec cavity, it strikes the photoconductor and frees sulating sheet, goes down one side of the pump electrons. They, in turn, begin to oscillate cavity, folds over, and returns on the other digital data link. The configuration thus re- mains the same for both VAB and pad opera- rapidly up and down within the material, in side. The cavity is the terminal portion of a direct response to the alternating electric field waveguide assembly, with microwave pump tions; only the length of the data link changes. The complex umbilical interface between the inherent in the surrounding microwaves. These energy being introduced at the other end. One electron oscillators control the amount of of two rutile paramagnetic crystals is shown vehicle and ground support equipment remains undisturbed until launch. The LCC computer microwave power that leaves the cavity. The in close proximity to the meander line, the variations in the incoming light are then con- ferrite isolator being on the opposite side of controls the sequence of checkout and launch countdown programs performed by the Mobile verted to intensity variations in the outgoing the meander line and not visible. In operation, microwaves. Conventional microwave tech- the entire structure shown in the photograph Launcher computer via commands transmitted over the data link. The "slave" computer in niques make it possible to process these vari- lies between pole faces of the superconducting ations. These techniques are similar to those magnet, which provides a precisely controlled turn performs the detailed testing and sequenc- ing, performs evaluation and data compression used in modern radar and commercial tele- and distributed transverse field, typically, of a vision systems. few thousand gauss. The assembly including of test results, and transmits the data back to the magnet is enclosed in a chamber main- the LCC computer which relays it to the cor- tained at 4.2°K. rect operator for display. LCC operators can override, via their console request keyboards, the predetermined sequence of programs stored Amplifiers with performance as described above are by no means the end, however. New in the Mobile Launcher computer or handle advances are in the offing through research in unusual test situations. These are only a few of the recent achievements which are indicative of the great range of activities in engineering and areas including optical inversion (pumping), operation at temperatures above 4.2°K, higher In addition to conventional serial computer science at RCA. To learn more about the many scientific functions, special parallel input/output capa- challenges awaiting bachelor and advanced degree candi- frequency operation, and the use of active bilities are included for control of 1008 discrete dates in EE, ME, ChE, Physics or Mathematics, write: materials in power rather than single-crystal (relay driver) outputs, monitoring of 1512 dis- College Relations, Radio Corporation of America, Cherry crete (contact closure) inputs, a wide range of Hill, New Jersey. DC and AC analog outputs (72 in quantity), a wide range of DC and AC analog inputs An Equal Opportunity Employer (300 in quantity), telemetry interface, 3 internal interval timers, several external clock inputs, and an interface with the spaceborne computer. In line with the developmental nature of the total Saturn program, the role of RCA's form. Saturn Ground Computer System is continu- ON PLANETARY LANDINGS BY SPACECRAFT One of the most important and fairly general sort of landing or- lying entirely within the atmo- difficult problems facing engi- bit. In order to deal with the sphere. (Fig. 1.) neers today is the problem of p r o b l e m on an undergraduate 3) This circular orbit will then planetary landings by spacecraft, level, however, we will find it decay extremely rapidly as the or, more specifically, the mo- necessary to introduce a good ship is braked strongly. The ship tions of spacecraft in the imme- many simplifications and sim- may deploy dive brakes to in- diate vicinity of a planet. In its plifying assumptions. It must be crease the deceleration. At pro- full generality, this p r o b l e m stressed at the outset that our per speeds and altitudes para- deals with such diverse aspects results can claim little or no ac- chutes may be deployed so as to as the motion of winged craft in curacy in describing the physical reduce the velocity to the lowest atmospheres* and the landing of situation, for our assumptions p o s s i b l e level. Retro-rockets the LEM on the surface of the will often only be gross approx- may be used for the final braking; moon. Few results can be stated imations and the mathematics which are completely accurate in will be restricted to elementary then the ship will touch down. this field, and inadequacies of differential equations. N e v e r - This landing approach, suitably knowledge are rather common; theless, this discussion may help limited, can be taken to be a recall how the spacecraft Molly give readers an introduction to fairly good description of land- Brown failed to develop its the- the subject, which they will later ing approaches which are in use oretically predicted aerodynamic follow up with more advanced now or are to be used in the im- lift and landed short of its tar- study. mediate f u t u r e . For example, get, and how the Russians' soft- Step 3 (except for the suggestion lunar-landing attempt of last Oc- The landing approach we will of dive brakes) is a fair descrip- tober failed because the retros consider has the following char- were barely off in their reduction acteristics: of the craft's velocity. 1) The ship approaches t h e The purpose of this series is planet: in its immediate vicinity to approach this topic in an intro- it can be considered to be under ductory manner. We shall con- the influence of only the planet's sider the problem of landing a gravity and its orbit with respect spacecraft on a planet which to the planet is a hyperbola. It posesses an atmosphere, using a passes through the atmosphere and is slowed to under para- bolic velocity; if its velocity when on the fringes of the at- * For example, the satellite Ti- mosphere is so high that drag tan of Saturn is known to have an would not slow it sufficiently, a t m o s p h e r e of methane. This rockets may be fired to slow the suggests a novel form of jet ship somewhat. plane, which would carry liquid 2) Having passed through the tion of the landing approach of all oxygen in tanks and get its fuel from the atmosphere. The aero- atmosphere, the ship swings out- U.S. and Soviet manned space- dynamics of such a craft in Ti- ward in an elliptical orbit of high craft launched thus far. Also, the tan's 100c Kelvin atmosphere eccentricity with perigee lying landing approach of the Apollo would be quite an i n t e r e s t i n g within the atmosphere. Thus the moonship may be taken to be de- problem to study. orbit will decay rapidly and will scribed by Parts 1 and 3, if we be reduced to a circular orbit CONT1NUIED ON PAGE 20 Whatever your interest in military or commercial elec- den's location in famous Fairfield County, Connecticut tronics may be, it is certain that you can satisfy offers a rare combination of cultural and sports activi- it at Norden: computer techniques, display integration, ties the year 'round. Parks, trout streams, golf courses radar systems, TV, IR, microelectronic or more con- abound. Close by is Long Island Sound. Hunting coun- ventional circuitry, stabilization and navigation sys- try and ski centers are within easy driving distance, as terms. Applications encompass advanced underwater, are a number of nationally known cultural events. Yet shipboard, aircraft and space vehicle systems and all this is only 41 miles from New York City. ground support complexes. There are openings in Design, Development & Manu- With Norden, you gain broad exposure to technical facturing. Electrical Engineers and Physicists gradu- aspects of a problem through our method of assigning ating in 1966 are invited to contact your College Place- projects to problem-solving teams. Our corporate- ment Officer to arrange an on-campus interview. Or financed GraduateE d u c a t i o n Program provides quali- forward your resume to: Mr. James E. Fitzgerald, fied engineers ample opportunity to continue formal Technical Employment Manager, at Helen St., Norwalk, education at nearby academic institutions. And Nor- Connecticut 06852. CONTINUED FROM PAGE 18. From this, we see that the tie them together by asserting drag forces on its velocity and number of moles per unit volume that the spacecraft is braked so distance traveled, and the effect = p/RT. But (no. of moles) (mol. strongly in ics first encounter of using retro-rockets. Some of wt.) = density; let m be the mol. with the atmosphere that its orbit these results will be familiar, wt. and we have f = pm/RT. If is reduced to circularity without or can be found in well-known we take T to be constant (is- the ship leaving the atmosphere references and texts; these r e - othermal conditions throughout again. sults we will do little more than the atmosphere) we have P pro- Step 2 could be useful in the state. Other results, less famil- iar, we will derive in full. The portional to p. Then case of a planetary exploration party landing on their planet. references for the more fami- They would want to conduct sys- liar results are as follows: P =P o e-(Po/P o ;gy tematic i n v e s t i g a t i o n s of the Halliday & Resnick, Physics But consider the term Po/po. We features of the planet, and arti- for Students of Science and En- have written P in terms of p; di- f i c i a l satellites could be ex- gineering (1952), John Wiley & vide both sides by p and we have temely useful tools in this ex- Sons that P / p - m/RT. This is a con- ploration. These satellites could Yeh & Abrams, Principles of stant. Our final result, then, is: be launched quite easily, into any Mechancis of Solids and Fluids p = p e -(m/RT)gy desired orbit, merely by ejecting (1960), McGraw-Hill them with a small boost at the Consider the variation in den- (1) proper time in the proper el- sity with increasing altitude of In using Eq. (1) we shall ordin- lipse. This would be analogous an atmosphere. It can be shown* arily be concerned withrangesof to antarctic explorers setting out that the variation in pressure altitude which a r e small com- overland to the Pole and leav- with altitude is given by: pared to the radius of the planet; ing instruments behind at various hence we may take g as a con- places on the trail to monitor con- p = P o e=(Po/P o )gy stant. ditions and radio them to the where p is pressure, p density, party of explorers. g the acceleration due to gravity, The implications of Eq. (1) are Of course, the descriptions of -Q the y altitude and the subscript extremely interesting. Let us land approaches in use today are of y = 0. Wethe denoting can initial condition apply the Ideal compare the variation in density highly idealized and limited in Gas Law twice to obtain for the planets Earth and Mars. their usefulness. For instance, the form F o r Earth a typical value for with regard to Part 1 we made we require. This very familiar s u r f a c e d e n s i t y is 1.2kg/- the "two-body assumption" that law may be written: pV = nRT. m e t e r s ^ , for temperature 300° K, we need only consider the two We note that n is number of moles and for g 9.8 m e t e r s / s e c 2 . The bodies of planet and spacecraft, and t h e r e f o r e represents the atmosphere of Earth is about 80% neglecting gravitational i n f l u - mass of the gas under consider- nitrogen (m = 28) and 20% oxy- ences of other bodies. Thus, any ation. Take V « 1 meter3; then gen (m = 32); hence we take a description of an Apollo landing V drops out of the equation, and weighted average and have for approach based on our model we write: p » nRT. the E a r t h ' s atmosphere m = 29. could only have any sort of va- F o r Mars a typical value for tem- lidity within a dozen or so radii p e r a t u r e is 250° K and for g 3.9 f r o m either Earth or Moon. m e t e r s / s e c 2 . Its atmosphere is Moreover, Step 3 is somewhat limited by the fact that it ig- nores lifting effects, which are important in the control of a re- turning Gemini. In addition, we will ignore heating effects on the spacecraft. Thus Parts 1, 2, and 3 should be considered to repre- sent an idealized model of the gross characteristics of a land- ing spacecraft. However, this model has one great advantage over a more exact (but more complicated) model: it can be treated using physics and math- ematics which are entirely fa- m i l i a r to the undergraduate reader. We will treat the three steps in detail in the second article of this series. Before this, how- ever, we shall consider certain principles and results which will be useful in our discussion. These preliminary results concern the nature of a planet's atmosphere, the nature of orbits, drag forces TURN ON TOMORROW Feel like We offer the best combination of opportunity, responsibil- being one of the brains behind the coming gas turbine ity and individual treatment. International Harvester is a age . or developing a new aircraft alloy . . . or finding 2-billion-dollar-plus annual business. We are the world's out how to feed 4 billion people? Try your genius at Inter- largest producer of heavy-duty trucks, a major producer of national Harvester, where computers and research are as farm and construction equipment, an important steel man- familiar as tractors and trucks. We are a company that ufacturer, too. POWER and the people who provide it are supplies mechanical power to a world that is increasing our lifeblood. We need engineers —especially mechanical, its Population by more than 60 million a year. Our horizons industrial, agricultural, metallurgical, general and civil are unlimited. But our immediate job is to attract young engineers. We probably need you. Interested? Contact your Placement Officer now for a date to see an IH people whoC a n m a t c h t h e i r s t r i d e s w i t h t o d a y ' s o n r u s h i n 9 representative when he visits your campus. Or if interviews are not sched- technology. We have engineering openings in research and uled, write directly to the Supervisor of College Relations, International Harvester Company, 401 N. Michigan Avenue, Chicago, Illinois 60611. development, design and testing, manufacturing and sales. BIG CHALLENGES BIG OPPORTUNITIES Designing this processing unit—one of the health field; a synthetic rubber having both a host of new challenges-and opportuni- largest of its kind in the world—was just the resilient qualities of rubber and the ties-for those who set for themselves the one of many recent challenges met and manufacturing versatility of plastic; a highest standards of performance. At overcome by Shell. And there are many retail marketing installation, the Shell Shell, they include graduates in many more waiting to be tackled. Your own Motorlab.forthe precise diagnosis of auto- disciplines, particularly engineering, chem- future at Shell can involve some of the mobile ailments; and a catalyst for rocket istry, geophysics, physics, geology, mathe- most challenging engineering, scientific fuels. and business problems in the world— matics and business administration. along with many of the broadest career Shell is experiencing such dynamic Shell representatives will be glad to opportunities. growth that it has become the fourteenth answer your questions about the Shell largest industrial corporation in the United Companies when they visit your campus- The diversity of Shell's interests is high- States in terms of sales. Growth is bringing lighted by several recent achievements of You also will receive full consideration if Shell people in providing new products, you send a resume to Manager, Recruit- processes and techniques in the petroleum ment Division, The Shell Companies, Dept- and chemical industries. These include: a E , 50 West 50th Street, New York, NX method of drilling and completing wells in 10020. An Equal Opportunity Employe water more than 1,000 feet deep; a medi- THE SHELL COMPANIES . Shell Oil Com- cine for the rapidly expanding animal pany . Shell Chemical Company • SheU Devel- opment Company • ShellPipeLineCorporation Campus research is important to Detroit Edison Detroit Edison supports research activities at many Research projects such as these provide a chal- engineering universities and receives valuable infor- lenge for both professors and students alike. This mation from these joint programs. Here are some of challenge continues after graduation in our re- the projects now under way at University of Michi- search laboratories and engineering departments gan, Iowa State University, Kansas State University because interesting things are happening at Detroit and Rose Polytechnic Institute. Edison. Power System Stability Analysis and Generator Field If you're graduating this year and want to put Control your ideas and energies to work —write to Mr. • Analysisi of Conductor Vibration George Sold, The Detroit Edison Company, Detroit, • Modern solutions for Power Networks Michigan 48226. And look for the Edison personnel • Mathematical Models for Peak Load Forecasting representative when he visits your campus. Block Diagram Representation of a Power Generat- ting Unit-a first step in stability analysis Thermionic Conversion Now let us consider the ec- Let us now consider the dynam- almost pure nitrogen; hence m = centricity E of the orbit. We will ics of a ship in flight through the 28. Measurements by the space use the following notation: At a atmosphere. The most important probe Mariner IV indicate a P 0 of particular time, v is the ship's drag force is proportional to the 1% to 2% of the Earth's; taking the velocity (measured with respect square of the ship's airspeed*; median value of 1.5%, we have to the center of the planet), r its this force arises from a physical Mars' surface density as 1.8 x d i s t a n c e from the center as model of the ship, with its blunt 10~2 kg/meters3. We have R, above, R the planet's radius, g heat shield, pushing aside gas the universal gas constant, as the acceleration due to gravity at which it encounters and thereby 8.32 joules/mole-°'K. Then we its surface, and O the angle be- transferring momentum from it- may put these values into Eq. tween the ship's velocity vector self to the gas. The shape of (1) to get the variation of den- and the radius vector (vector the spacecraft is quite impor- sity for the two planets: from ship to center of planet). tant; the optimum shape is that For Earth: P = 1.2 e-0.H6y The eccentricity may be found of a cone or conic frustrum. kg/meters3 from^ Such a shape places the center For Mars: P = 0.018 e -°- 0 5 2 5 y of gravity close to the heat shield kg/meters^ E 2 = v 4 r 2 sin 2 0 - 2v2r sin 2 0 + 1 and makes the shape much more stable and less likely to tumble.5 where y is measured in kilome- g2R4 gR2 t e r s . These e q u a t i o n s are For our problem, however, we Let the area of the heat shield graphed in Fig. 2. will be most interested in the case be S, and let the heat shield be of near-normal incidence, 9 7=^ fairly flat. The density of the From this graph we observe a atmosphere at the point under very interesting result: that while If/2. Then the sin2© terms are close to unity and we have: consideration is p and the air- initially Mars' atmosphere is speed of the ship is U. Thus in much thinner than Earth's, above e - ± (v 2 r/gR 2 - 1) where the ambiguous sign is de- time t the ship will sweep out a 67.2 km (41.7 mi., or 220,000 volume SUt, and will encounter a feet) it is actually denser. This termined by the stipulation that E>0. (3) mass of gaspSUt; the ship's rate suggests that if we could build a of mass encounter is then PSU, vehicle which would do most of Suppose a ship, far out in its decelerating above the 42- Each element of gas, in being space, is approaching a planet pushed aside, has its velocity mile limit in landing on Earth, with velocity v°, the velocity then this vehicle would also do relative to the ship, along the di- vector pointing approximately in rection of the ship's motion, re- most of its decelerating in Mars' the direction of the planet. Let atmosphere in landing on that duced an amount kU, where k is the ship fall to a distance r a constant that represents the planet. from the center; its velocity will average reduction for all the ele- Now let us consider the dynam- be equal to the sum of v 0 and ments of gas that the ship en- ics of a spacecraft under a plan- counters. Then the rate of mo- et's gravitational field. From the value of the escape velocity mentum gain by the gas iskPSlr. Kepler's first law we know that at that distance r. It can be shown But this is then the drag force on in the absence of dissipative or that v escape - >/2~vc, wherev c is the ship. We call F d the drag force drag forces, the orbit of the the circular velocity (velocity and write spacecraft will be a conic of ec- required for a circular orbit) at centricity E with one focus at the F d = kfSU2 that altitude. But this velocity As a point of interest, a mod- center of the planet. The equa- may be found from Eq. (3), by tion of such an orbit is: 2 ification of this equation is used setting E = 0 and solving for v. quite extensively in the field of L The v c = ^2gR2/r. So we have aerodynamics. The modification r = 1 - E cos 0 is as follows: where r is d i s t a n c e from the for the velocity of the ship center, o is measured from the F d = 1/2PU2SCD perigee of the orbit, and L is a where S is taken to be the total v = vo * J2gR2/x (4) surface area normal to the di- constant, c a l l e d the semilatus rectum of the conic. It can be rection of flight and CD is a con ' seen from this equation that r stant, called the coefficient oi takes its minimum value at the drag. As concerns our problem, ^Yeh & Abrams, pp. 167-168 C D has been calculated for the perigee; denote the perigee by ^Yeh & Abrams, p. 169 rmin. Then L - (1- E)rmin and case of subsonic flight througn ^The author is indebted to Mr. an atmosphere; it has a value ot we may write as our equation of Gary Irving of Douglas Aircraft the orbit: 1. It can also be calculated for the Corp. for this discussion of the case of flight through an atmo- r *r 1 +E stability and optimum shape of sphere that cannot be treated as min 1 - E cosft(2) spacecraft. a continuum but must be treated As an application of this equa- * The airspeed is the velocity as a collection of discrete par- tion, we note that for an ellip- realtive to the atmosphere; it is ticles; from the theory of e l a s t i c - tical orbit the apogee, r m a x , is the velocity v plus a correction collisions it can be shown that to be found atjfi = -ft ; hence we for the speed of rotation of the for this case C D = 2. For tne find that planet. We will denote the air- highly important case of hyper r r 1+ E speed by U. The concept of air- sonic flight through a continuum, •"•max = x m i n \ _ j? speed will be discussed at greater however, C D has not been cal- 2 length in the second article of this culated; it must be determined Yeh & Abrams, pp. 166-167 series. CONTINUED ON PAGE5 There was a time when engineering an alternator automotive electronic equipment to do things for the system was an impracticality. Most everyone in the car that are impractical to accomplish mechanically. business tried i t - n o one could successfully mass Transistor ignition systems and electronic tach- produce the automotive diode —the key to the sys- ometers, hour meters for trucks and stereo tape tem. Finally, Motorola engineers made the break- decks, all-in-one air conditioning and heat control through-alternator systems are committing hapless systems — these are a few of the projects currently generators to the museum showcase. in motion with Motorola automotive engineers. Today, alternator systems are designed for auto- The car radio? Sure. Motorola makes that too. Paul motive, industrial, and marine use. Galvin mass produced the first ones in 1929 . . . to This sort of engineering sophistication is producing start a little business. The Company's first engine, the Wasp; to the air on May 5, 1926. Within a year Wasp set its first world record and we to smash existing records and set standard for both land and seaplanes for , come, carrying airframes andpilotshigh fartner, and faster than they had every before. Take a look at the above chart; then a good long look ship in fields such as gas turbines, liquid hydrogen at Pratt & Whitney Aircraft—where technical careers technology and fuel cells. offer exciting growth, continuing challenge, and lasting Should you join us, you'll be assigned early responsi- stability-where engineers and scientists are recog- bility. You'll find the spread of Pratt & Whitney Aircraft's nized as the major reason for the Company's con- programs requires virtually every technical talent. You'll tinued success. find opportunities for professional growth further en- hanced by our Corporation-financed Graduate Educa- Engineers and scientists at Pratt & Whitney Aircraft tion Program. Your degree can be a BS, MS or PhD in: are today exploring the ever-broadening avenues of en MECHANICAL . AERONAUTICAL . ELECTRICAL . CHEMICAL ergy conversion for every e n v i r o n m e n t . . . all opening Up n e w ENGINEERING • PHYSICS • CHEMISTRY • METALLURGY avenues of exploration in every field of aero- • CERAMICS • MATHEMATICS • ENGINEERING SCIENCE OR space,marine and industrial power application. The APPLIED MECHANICS. tecnnical staff working on these programs, backed by For further information concerning a career with Pratt In recent years, planes powered by Management's determination to provide the best and & Whitney Aircraft, consult your college placement & Whitney Aircraft have goneonto most advanced facilities and scientific apparatus, has new standards of performance inmuchalready given the Company a firn foothold in the cur- officer—or write Mr. William L. Stoner, Engineering same way as the Wasp had done in Department, Pratt & Whitney Aircraft, East Hartford, 1920's. The 727 and DC-9 are Indication rent land, sea, air and s p a c e P r ° g r a m s s o v i t a l t 0 o u r country' Connecticut 06108. s future. The list of achievements amassed the new family of short-to-medium by our technical staff is a jetliners which are powered by the veritable list of firsts in the successful JT8D turbofan. Example development of compact power plants-, dating back to current military utilizations are the the first Wasp engine which lifted the United States powered Mach 3 YF-12A which established four world aviation records to a position of world leadership in aviation. These the advanced TF30-poweredF-111various engineering and s c i e n t i f i c achievements have enabled geometry fighter aircraft. the Company to obtain its current position of leader- MEASURING THE GASOLINE RATING SEVERITY OF TEST AUTOMOBILES ABSTRACT signed. The octane numbers are fined as the knock-limited spark assigned to fuels on the basis of advance. The relationship be- In order to meaningfully in- comparison with Primary Refer- tween spark advance and octane terpret the results of a gas- ence Fuels (PRF's) which con- quality is found by running var- oline antiknock rating program, sist of varying mixtures of iso- ious Primary Reference Fuels of a measure of the rating sev- octane and normal heptane. These known octane number and de- erity of the test automobiles must r e f e r e n c e fuels, quite unlike termining the knock-limited be used. A method comparing the commercial gasolines, have a spark advance of each. By com- rating of a standard fuel to the singular boiling point. An auto- paring these spark settings with cars' basic requirements was mobile with manifold distribu- those of the test fuels, the test found to account for the mani- tion problems has trouble per- fuel road octane numbers are fold distribution differences of forming on the PRF's. A high found. the cars in the analysis. This road octane rating for a part- The standard fuel which was method also indentified the cars icular test fuel may not neces- also run in each of the cars which are best suited for rating sarily imply a high antiknock was an ASTM 99.6 RON Stand- the antiknock quality of gaso- quality for the fuel, but rather a ardization Fuel. This fuel was line to be used in normal pro- "dislike" of the PRF's by the 24% toluene and had an 11.5 duction cars. car in which it was tested. The sensitivity. A measure of the rat- Thomas A. Hewett differences in the manifold dis- ing severity of each car may 521 Ardson Rd. tribution characteristics of cars best be shown by comparing the East Lansing, Mich. can then be held to account for PRF octane requirement at basic 48823 much of the inconsistency in timing with the road octane num- road ratings on a particular fuel. ber of standardization fuel. A A basic requirement of any In order to best interpret the car which rates the fuel much gasoline antiknock rating pro- octane number results of a given above its requirement is not gram is that a meaningful in- gasoline rating program, some considered severe, while one terpretation of the calculated r e - means of measuring the rating which rates the fuel near or be- sults is possible. The lack of severity of the test cars should low its .requirement may be re- repeatability of the road octane be used. In a recent program garded as q u i t e s e v e r e , This rating of a single fuel by dif- consiting of sixteen test fuels method, in effect, compares the ferent cars has tended to cloud which were run in seven test auto- knock-limited spark advance of the meaning of road octane num- mobiles, an ASTM standardiz- the standardization fuel to basic bers. Also the fact that there is ation fuel was used for this pur- timing on an octane scale. Simple no standard method for deter- pose. comparison of the knock -limited mining the suitability of a partic- spark advance would not be effec- ular car for road rating had The road octane rating of the tive because the difference in lead to additional confusion in fuels was done by the Modified spark advance for a one octance this area. Uniontown method. This method number fuel difference varies An analysis of the differences consists of top gear, maximum between cars. The effectiveness throttle (without downshift) ac- in road octane rating of different celerations at different spark ad- of comparing the PRF require- cars should first be directed at vance settings. The spark ad- ment of each of the cars is lim- the reference base from which vance at which knock is pre- ited by the manifold distribution the road octane numbers are a s - sent at a trace intensity is de- problems indicated earlier. Sophisticated, work-saving aids help Bell System engineers provide important communications services As an engineer your future could be important to us. engineer selects a number of alternative plans to be You might be able to contribute to our continuing analyzed in detail by a computer. His final decision Is leadership in the communications field. Therefore, you based primarily on an analysis of the computer output. should know something about us and how we operate. The computer supplies more significant data, and Bell System engineers deal with modern problems supplies it much faster, than laborious, manual cal- in modern ways. They have at their command the culation methods. The engineer is thus relieved of latest in technology and equipment. dull, time-consuming computation, and he plans facili- An example is how computer programs aid in ties with increased confidence—knowing that he is providing telephone service for new communities. providing efficient and economical communications, tailored for a given area. Engineers at Bell Telephone Laboratories have devised computer programs broad enough in scope You may well find a rewarding career in the Bell so that Bell System operating telephone companies System, where people find solutions to exciting can use them to engineer the required wide variety problems. The Bell System companies are equal of telephone plant networks. opportunity employers. Arrange for an on-campus interview through your Placement Office, or talk to As part of a continuing effort, programs have been a local Bell System company. designed to analyze communications needs of an area for determining the best plant network layout and switching office location. In general, the necessary data are collected and the CONTINUED FROM PAGE 28 Examination of this table r e - predicting the performance of The results of this type of veals that the Buick Electra and a fuel in normal cars on the road, comparison for the seven cars Pontiac Catalina are particularly The importance of having a used in the program are shown well suited for evaluating fuels. measure of a car's rating se- in the following table. The cars These two cars rate the test verity can now be seen. If gas- are listed in order of decreas- fuels in a spark advance range oline antiknock quality informa- ing severity with the difference which is quite close to basic tion is to be used for determin- between the standardization fuel timing, or under conditions quite ing g a s o l i n e production stan- rating and the PRF octane r e - close to normal customer usage. dards, then ratings which are rel- quirement shown for each. Thus, the antiknock quality infor- evant to customer usage must be ORDER OF RATING SEVERITY mation generated by these cars employed. The advantage of IN TEST CAR FLEET provides a good prediction of the method like the one described St. Fuel fuel p e r f o r m a n c e which cus- above is that the effects of the Ratinq tomers will find in normal car manifold distribution character- NO. AUTOMOBILE M m u sp R F operation. The cars further down istics of the cars are eliminated. Req't the rating severity scale eval- By considering the antiknock rat- 1 1965 Buick Electra 225 0.2 uate the fuels in a spark ad- ings of the test fuels in conjunc- 2 1965 Pontiac Catalina 1.0 vance range which is quite dif- tion with the test cars' rating se- 3 1965 Chevrolet Impala 2.1 ferent from basic timing, or nor- verity, a meaningful interpreta- 4 1964 Buick Special 2.1 mal operating conditions. Anti- tion of the calculated results can 5 1965 Ford Galaxie 500 3.2 knock quality information derived be made. 6 1964 Ford Fairlane 500 4.1 from ratings in these cars does 7 1965 Dodge Custom 880 4.8 not have much significance for Allied Chemical's product list now tops 3,000 World War II now account for a quarter of —and is growing fast! sales. There's tremendous variety: Building materials. Fashion fibers. Rocket fuels. Dyes. Such product diversity means not only many Fertilizers. Plastics. Petroleum products. jobs, but many kinds of jobs to suit your tal- ents and inclinations. It means more top jobs, Over 35,000 people work in Allied Chemical's and more chances for advancement. It's one 10 divisions—at more than 100 plants and re- of the important things to look for when search centers—at scores of sales offices you're choosing a company. throughout the country. Allied Chemical is directly in- It's a big company with big op- volved with today's most signif i- portunities—and a good one for cant areas: agriculture, space, and nuclear energy. Some of its making a career decision. Ask products are basic—many are your placement office when our new. Products introduced since J interviewer will be on campus. 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Uses for these products number ing shovel, a telephone cable-laying At the Timken Company you in the growing thousands. ship now crossing the Pacific, space receive up to four years' training in There are 31 Timken Company exploration, the Spirit of America one or more of 22 training programs domestic sales offices in the United race car, the Alweg Monorail, a — 80% of which are for young States and Canada. Practically every moveable grandstand for the new engineers. major city has one. District of Columbia Stadium, Atlas Instruction takes place on the job We serve markets in 170 countries missiles and defense work— and in the classroom. With pay. And from 14 manufacturing plants in They're all recent projects involv- we participate in executive develop- England, France, Australia, South ing The Timken Roller Bearing ment programs at well-known uni- Africa, Canada, and the U.S. Company, world's largest manu- versities. And we're still growing. facturer of tapered roller bearings If you come with us, you can be So if you're interested in our kind and a leading producer of fine alloy an indoor-type working in straight of work, why not get in touch with steel. research, testing and production. Or us? Write Dept. MC for our 12-page The Timken Company is the you can be an indoor-outdoor-type career booklet. world's largest because our engi- and become a sales engineer, helping The Timken Roller Bearing neers developed tapered roller bear- customers solve their design prob- Company, Canton, Ohio 44706. An ings that revolutionized our "meat lems, which are also ours. equal opportunity employer. Often a problem upon solu- invariably settle down to the end- nominator; although the mere tion will reduce itself to the less repetition of a certain s e - presence of three as one of the reciprocal of a certain number. quence of one of more integers. prime factors does not assure a Insofar as a course in mathe- Some examples of exact deci- constantly repeating single inte- matics is c o n c e r n e d , it is mal fractions are: ger as it does in the examples common to leave the expression mentioned here. in that form. We recognize, of 1/5 =0.2. 1/16 - 0.0625. Another form of never-ending course, that the reciprocal of decimal fraction repeats a cer- any given number is in itself 1/125 =0.008. 1/4,096 - 0.000244140625. tain small group of integers. a precise number and can rep- resent the exact answer to a The exact decimal fractions are 1/11 = 0.09 09 09 09 particular problem. For ex- relatively uncommon. They stem 3/22 = 0.136 36 36 36 ample, an exhaustive nationwide from just those denominators 1/55 = 0.018 18 18 18 survey may show that one doctor that contain no prime factors Nevertheless, the decimal in thirteen smokes cigarettes. other than two and five. There fractions which repeat a some- It is graphic, dramatic, and ac- are but 40 such exact decimal what lengthy sequence of integers curate to state that only 1/13 equivalents of the reciprocals for over and over again are more of the nation's doctors smokes all integers up to and including interesting. We have reference cigarettes. It makes little more 4,096, the last example cited to decimal fractions of the forms: sense to say that only 7.69 per above. This is one of the lia- cent of the nation's doctors smoke bilities resulting from the use of 1/7 = 0.142857 142857 142857 cigarettes. However, there are 10 as the base of our number many instances when the decimal i/13="o. 076923 076923 076923 fraction form of answer is to be system. If we used either 12 preferred despite the loss of an as the base of our number sys- exact solution when the conven- tem, for example, the frequency These decimal fractions are par- tional three or four significant of exact reciprocals would in- ticularly unusual. They appear figures of the answer are shown. crease very substantially. as the reciprocal of a prime Some never-ending decimals number. The preceding statement The decimal equivalents of all that repeat the same integer may be challenged as not apply- integer fractions fall into two after one or more places are: ing in the instances of the prime rather obvious classes. They are numbers 2, 3, 5, and 11 * either exact decimal fractions 1/3 = 0.3333333333. . . 1/45 = 0.222222222. . . have been referred to above. which may be expressed in a Nevertheless, this has been found finite number of places, or they 1/576 = 0.0017361111. . . to be true of a large number are never-ending decimals. It These decimal fractions appear of primes. We shall soon see may not be so obvious, however, only if the integer three is one why this must be true. that the never-ending decimals of the prime factors of the de- CONTINUED TO PAGE3 Through these doors passes some of the finest Engineering & Scientific talent in the country This is the main entranceway to Allison's 217-acre R & D complex... a complete facility for the design and development of advanced aerospace and power trans- mission products. Accelerated activity in military pro- jects—coupled with an expanding volume of work in the commercial field—opens challenging opportunities for young engineers in this creative climate at Allison. Perhaps there's a place for you on this Allison-GM team. Talk to our representative when he visits your campus. Let him tell you what it's like at Allison, the Energy Conversion Division of General Motors. Or, send for our brochure describing the opportunities: Mr. R. C. Martz, Personnel Director, Allison Division of General Motors, Indianapolis, Indiana. An equal opportunity employer. CONTINUED FROM PAGE 34 ond half of the sequence arranged Thus, once the repetitive se- Imagine the example of 1/7. under the first half: quence is recognized, the re- The largest remainder that can 1/17 = 0.05882352 94117647 sult may be written down to be brought down from a step 05882352 94117647 any desired number of places. of division is the number 6. The _9_4117647 smallest remainder is the num- A working knowledge of the ber 1. A remainder of zero would 99999999 d e c i m a l equivalent of integer indicate that 1/7 can be expressed 1/19 = 0.052631578 947368421 fractions may be used to good as a finite decimal fraction. We 052631578 947368421 .... advantage on a great many ap- realize, of course, that this can- 947368421 plications. We will recall PART not be true. It stands to reason, 999999999 I, FUN WITH SQUARES, where therefore, that the remainder it was pointed out that the dif- from a step of division will be This feature, when put to work, ference between the squares of forced to repeat after not more makes it possible to express the two consecutive integers is sim- than six steps. You see, above, final (n - 1) places of the deci- ply the sum of the two integers. that this is precisely the case. 2 Turning t h e s a m e statement mal sequence for the^rimejiunt-- around, we have a method at In the example of 1/13, the ber, n, simply By inspection. hand that is useful in finding remainder after six trial divi- From the foregoing it is hoped square roots rather than squares. sions is the number 1. But this that a little interest has been We might reason that 13 lies is how the problem began! The aroused that will cause you to somewhere between three and cycle simply must repeat itself. familiarize yourself with the first four; being very nearly 4 , or dozen reciprocals. From a work- ing knowledge of a few recipro- 3 + 4 Another property exhibited by cals, a great many others can 4/7, of the interval from three these repeating decimals is that be found. to four. Our new interest and the fraction begins to repeat itself For instance, the reciprocal experience in handling decimal after the nth place in the exam- ple of 1/n, where n is a prime of 15 is merely one-third of the fractions indicates the answer to be close to 3.6. Ordinarily, one number. The decimal fraction reciprocal of five. We may read- would not be interested in ex- of 1/13 repeats itself in the ily establish, tending the approximation into thirteenth place, the "double fre- 1/15 = (l/3)(l/5) = the third significant figure since quency" notwithstanding. Simi- 0.2000 ° 0.0666. . . . the data furnished and the ap- larly, the decimal fractions rep- 3 proximation method involve only resenting 1/17 and 1/19 repeat Similarly, one and two place numbers. The themselves in the seventeenth 1/14 - (1/2X1/7) - actual root, to five significant and nineteenth places, respec- figures, is 3.6056. tively. 0.142857 142857 2 = 0.07 142857 142857. A n o t h e r example is >/l58. The interval of the cycle al- and This number lies between | ways involves an even number 1/18 > (1/2X1/9) = and 13. We e x p e c t it lies of decimal places. This would 0.11111. . . . near 14 , or 14/25, of the appear to be a condition im- 2 12 + 13 posed by meeting the require- interval toward 13. Expressing ments of beginning to repeat in = 0.055555 three significant figures, the an- the nth place, where n must Note the persistence of the se- swer is quickly estimated to | necessarily be odd if the number quence, in reciprocals 12.6. Attempting to stretch out is to be any prime other than involving 142857, seven as a prime factor a fourth yields 12.56. The actual two. of the number. root is 12.5698. Once the form of the cycle has Having established that these been established, it may often We sense now that our method cyclic groups always contain an be applied in expressing decimal r e s u l t s in answers that are even number of digits, we may fractions where the numerator is slightly in error, a fact whic divide them into two equally long an integer other than one. The can be verified by comparing integer groups and demonstrate following sequences are illustra- the actual parabolic function,y another property which we shall tive: x2pbetween any pair of consecu- call "being complementary with 1/14 = 0.07 142857 142857 tive integers with the straight respect to nine about the mid- 2/14 = 0.142857 142857 " ' line approximation method w point." We recall the sequence, 3/14 = 0.02 142857 142857 are substituting in its place.Th 142857, representing the deci- 4/14 = 0.2857 142857 comparison will also reveal tha mal equivalent of 1/7. The sum 5/14 = 0.3 57 142857 " ' the a c c u r a c y improves whe of the two parts, 142 and 857, 6/14 - 0.42857 142857 bigger numbers are involved is 999. The six-figure group which repeats in the instance of 1/18 = 0.055555 A simplifying, and often cor- 1/13 may be written in two parts, 2/18 - 0.111111 rective, step that can be take 076 and 923. Again, they add up 3/18 = 0.166666 when working with larger num- to 999. The same may be said 4/18 = 0.222222. '. \ bers such as ./9T7 is to assume for the reciprocals of 17 and 19 5/18 = 0.277777 which appear below with the sec- 6/18 = 0.333333' that (30 + 30) in the fractioned CON T I N U E D TO P * G Four years and 88 million dollars later... In the last four years you've been studying, Collins' every area of communication, computation and con- total sales rose from $190 million to over $278 mil- trol. It's a broad field. And an exciting one. One lion — up 88 million dollars. where a young man like yourself can carve out a The number of people working at Collins climbed financially rewarding and professionally satisfying to 16,662 — u p 2,000. career. In the past four years, we've invested over 52 Collins is one of the few companies offering you million dollars in new plants and equipment as part such a diversity of opportunity because Collins is of our continuing expansion program. one of the few companies so totally committed to Our products are used by governments, business the broad spectrum of the communication, compu- and industry throughout the free world. tation and control concept. This brief picture of company growth means We'd like to tell you more about our company, something very special to you. Opportunity. about our growth, about the opportunities we can of- We are working on basic research designing new fer you. For complete information contact the Collins equipment and systems, and producing products in representative on campus. Industrial News The Universal Technical Products Co. announces a new universal hand tool . . Triceps. This remarkable, all stainless steel instrument eliminates many of the problems encountered by those who work with very small, delicate, oddly shaped, or otherwise difficult to handle objects. Depressing the Triceps plunger causes three resilient, hooked fingers to flare out from the tip. By properly positioning the extended fingers and releasing the plunger, the fingers retract and an object is firmly but gently grasped. This instrument is ideal for hand- ling small parts in cramped locations or for holding components during soldering operations. It is very effective in applications where it is necessary to pick up flat objects from a flat surface, and is most advanta- geous when minimum contact area between the tool and and an object is desired. A new solventless varnish from General Electric has greatly eased the varnishing operations in- volved in the production of electric motors. The stator on the left has been treated with new G-E "Series 700" Solventless Varnish. Because the varnish is applied only where it is needed, there is no excess varnish to be removed and stator can be assembled directly into a motor. The stator on the right was treated by dipping into a solvent containing varnishes. The strings caused by drain- ing must be removed and the stator must be cleaned before assembly. Scientists of International Business Machines Corp. have found that by rolling different sized balls into an inclined tray, they can duplicate what happens when ctoms from metallic vapors are frozen directly onto a cold surface. Such films do not follow the traditional rules of metallurgy because they are deposited directly from a vapor without going through a liquid stage. The model S h o w s for example that if the diameter of the bal Is differs substantially, the balls will arrange them- selves into an amorphous or homogeneous structure. These and other insights gained from the model are in Qualitative agreement with behaviour of atoms in the formation of these new films Industrial News The FairchiId Controls Stan system for determining an aircraft's take-off gross weight and center of gravity has com- pleted intensive testing aboard a Pan American World Airways cargo jet. These tests were highly successful. Shown in the upper left photo is the location of the Stan pressure trans- ducers on the landing gear. Lower left is a close-up of the left main landing gear showing the transducer installation. Pressure from the hydraulic fluid in the struts is sensed by the transducers and translated into electrical signals. Upper right photo shows nose gear installation of transducers. Elec- trical cabling from the transducers runs directly to flight sta- tion and into the Stan indicator box shown in lower right photo. Here two digital indicators display the Take-Off Gross Weight in pounds and the Center Of Gravity in Percent of Mean Aero- dynamic Chord. Manufactured in the U.S. under license from the Socony Mobil Oil Co., this Unico Chloride-ion Test Kit is an inexpen- sive, reliable, and rapid method of measuring chloride-ion concentration in many applications. When testing the sample is collected in the test vial. An indicator tube is inserted into the vial. A yellow stain appears if the ion is present and the length of the discoloration in the tube indicates the concentration present. The Unico Chloride-ion Test Kit will measure potassium, magnesium, and manganese chlorides as well as sodium chloride. A two-transistor glass flar pack has been intro- duced by the Electronic Products Division of Corning Glass Works. The customer made a hermetic seal between the 9 l a z e d lid and the glass case after in- sterting the d e v i c e s . The package uses Corning Code 7052 glass, black so that it blocks our infrared and visibie radiation. Besides transistors, the package can be used for hermetic protection of other miniature devices. D i m e nsions are .240-inch square and .060- inch thick after sealing. from the ocean floor to the moon...and beyond Hughes sphere of activity extends from the far reaches of outer space to the bottom of the sea . . . includes advanced studies, research, design, development and produc- tion on projects such as: © SURVEYOR —unmanned, soft-landing lunar spacecraft for chemical and visual analysis of the moon's surface; © SYNCOM (Synchronous- orbit Communications Satellite)—provides world-wide communications with only three satellites; © F-111B PHOENIX Missile System—an advanced weapon system designed to radically extend the defensive strike capability of supersonic aircraft; © A n t i - ICBM Defense Systems —designed to locate, intercept and destroy attacking enemy ballistic missiles in flight; © A i r Defense Control Systems— border-to-border con- trol of air defenses from a single command center—combines 3D radar, real-time computer technology and display systems within, a flexible communication's network; © 3D Radar—ground and ship-based systems give simultaneous height, range and bearing data—now in service on the nuclear-powered U.S.S. Enterprise; ©POLARIS Guidance System — guidance components for the long-range POLARIS missile; ® Hydrospace — advanced sonar and other anti-submarine warfare systems. Are you ready to test your engineering knowledge with practical problems ? Stretch your mind at John Deere. You'll work on practical solutions to the challenge of developing new machines, materials and manufacturing methods. Vigorous growth in agricultural and industrial markets, both in the U.S. and overseas, offers vast opportunities for John Deere engineers to test their ingenuity and develop their ideas. John Deere has a 128-year tradition of growth and leadership. To continue this record, we need college graduates interested in product design, research, materials analysis, industrial engineering, methods, plant engineering, and reliability engineering. You'll find job opportunities match college majors in most areas of mathematics, science and engineering. You'll work for one of America's 75 largest corporations . . . first in farm machinery sales in the U.S. Yet, you'll retain many advantages of a small company. Our long-time policy of decentralization encourages initiative, ability and leadership. As an engineer, you'll receive project responsibility as rapidly aS y o u can earn it. F °r more information, check your college placement office . . . or write: Director, College and University Relations, De ere & Company, Moline, Illinois. An equal opportunity employer. CONTINUED FROM PAGE 38 indicated division for each of A further interesting method denominator is very little dif- the algebraic fractions. for determining reciprocals may ferent from (30 t 31). Hence, \.... = l 4 X + x 2 + x 3 + x4f be explained by assuming the JWf - 30 * 27/60, or 30.45. 1 -x problem of 1/41. We first rea- Actually, to four decimal places, +x n+ . . . son that the desired reciprocal the answer is 30.4467. — L _ = i - x +x 2 - x 3 +x 4 - is close to 1/40. We readily similarly, if_we desire the 1 +x n recognize the latter as being solution of v/888, we may con- n 0.0250. Just how far removed +(-x) -.... clude the number lies close to from 1/40 a r e we? Performing 30, but is nearly 12/60 of the Thus, 1 • \ the subtraction to see what dif- interval toward 29. Our solu- 0799 1.00-0.01 ference there actually is, il.m suggests 29.80 as the root. = 1+0.01+0.0001+ The more exact solution ob- - 1.0101 m tained by extraction of the root 40 4 1 " 41 x 4 0 " 1,640 is 29.7993. A typical slide rule Therefore, answer for the above problem T7O2 1.00-0.02 will be no better than the r e - - 1-0.02 + 0 . 0 0 0 4 - . . 4 T = 4 ^ 1 ^ 4 0 =0.0250-0.0006 sults obtained by the suggested S 0.9804 method. = 0.0244 Application may be made with Calculating the reciprocal to a As a general rule, the ap- problems involving 9.9 and 102, f e w more p l a c e s reveals proximation is both easier and or any other similar values, 1/41 - 0.024390. more accurate in working from where proper regard is given to the perfect square nearest to the Similarly, we may estimate the number given under the radical. the location of the decimal point. reciprocal of 79, As an example, y/24B may be To show the limit of these estimated as being 15 + 23/30, methods where four significant or 16 - 8/32. The solutions are f i g u r e s a r e desired, several respectively, 15.77 and 15.75. values are tabulated below. The JJ 0.01266. The actual root is 15.748. 79 identities i n v o l v e geometric It matters little whether the pro- Having observed that the ac- s e r i e s w h e r e each additional curacy of the approximation duct of 79 x 80 is evaluated or term increases the number of whether 6,400 is used in de- method improves when working decimal places by two. We have with larger numbers, we have shown three terms of each series termining the difference between reason to return to the original so that we may properly a p - these two reciprocals. In the example, y/13. Should we be able praise the effect of the third more r e c e n t instance the to extract the square root of term upon the last significant magnitude of the second term 1,300, a d d i t i o n a l significant decimal place. is but little more than one per figures will be obtained. It is cent of the first term. A 1 a simple matter to point off the x - 0.05 x = 0.07 x = 0.09 percent to 20 per cent error decimal place that represents in the determination of this in- tin' difference between yT3 and 1/0.95 1/0.93 1/0.91 crement scarcely affects the sig- /1300. nificance of the answer as or- 1.000000 1.000000 1.000000 dinarily reported. Recalling methods from PART Fun with reciprocals need not I, FUN WITH SQUARES: 0.05 0.07 0.09 be limited to these few methods. 35 2 . (3)(4)100 + 25 =- 1,225 Imagine the example of I/47 0.0025 0.0049 0 0081 As a first approximation, we ca and 36 2 - 352* 35 + 36 0.000125 0.0Q0243 0.000729 treat this as 1/50, for which - 1,225 * 71 - 1,296 we know the reciprocal to be i hug 1.053 1.075 1.099 0.02. Now, in making this rash /I^TOO •= 36 f 4/72 substitution, we have used a de- - 36 + 1/18 It is not until x • 0.09 that the nominator that is too large by - 36.0555. . . = 36.056 third place of the decimal is 3 parts in fifty or 6 per cent. Removing the factor of ten, our affected by the third term of Is it not true, then, that the solution now checks precisely the series. Actually, because of numerator is too small by 6 with the four-place calculation c o m m o n familiarity with the per cent? Again, it is a simple cited heretofore: v f 3 « 3.6056. squares and cubes of 11 and m a t t e r to i n c r e a s e the ap Returning now to finding r e - 12, the method may be used to proximate answer of 0.02by6 ciprocals, mention is made of determine per cent, yielding 1/47*0 0212 two other types which can be The answer to four significant handled with relative ease af- ter a little practice. They are U®M l/O88_ figures is 0.02127. of the form, l 1 and l -U 1.12 If we return to the reciproca 1 x - 1+ x of 7, we note another unusual 0.0121 0.0144 feature in the sequenceofin- where x is a small number when compared with one We may e s - tegers, 142857 142857. Starting tablish identities helpful in these iiill 0.001728 with the first pair, '14,"we instances by carrying out the 1<123 note that each succeeding pair 1.136 Want the opportunity to explore your discipline? At Douglas, your discipline is your own to explore, enrich, expand. You'll ' work in our extensive and exceptional Southern California facilities, where there are many independent research and development programs underway. You'll be near fine colleges and universities, where you can study for advanced degrees. If you want to publish a paper, we'll encourage it. In fact, we encourage anything that means professional growth for a young scientist or engineer on his way up. Send your resume to L. P Kilgore, Corporate Offices, Box 700-K, Douglas Aircraft Co., Inc., Santa Monica, California. An equal opportunity employer Men on the move at Bethlehem Steel Have you heard about all the opportunities for engineering and other technical graduates at Bethlehem Steel? You'll find a great deal more information in our booklet, "Careers with Bethlehem Steel and the Loop Course." You can ob- tain a copy at your Placement Office, or drop a postcard to Manager of Personnel, Bethlehem Steel Corporation, Bethlehem, Pa. 18016. National Security Agency of full-time graduate study at full salary. Near- ly all academic costs are paid by NSA, whose proximity to seven universities offering a wealth of advanced courses and seminars is an additional asset. IN-HOUSE TRAINING. The new NSA em- ployee first attends a six-week general orien- Outstanding Colleagues tation program, followed by a period of spe- cialized classroom study designed to broaden You will work alongside people of enor- familiarity with an area or areas of heavy NSA mously varied backgrounds and intellectual concern (e.g., communications theory, crypt- interests, over 500 of whom hold advanced analysis, computer logic and analysis, solid degrees. state physics). Formal study is complemented Researchers at NSA also receive constant by on-the-job training, as you work and learn stimulus from outside the agency. To assist in under the guidance and direction of highly certain program areas, NSA often calls on experienced associates. special boards of consultants—outstanding PROFESSIONAL ASSOCIATIONS, TRAVEL. scientists and engineers from industry and The agency fosters a climate of recognition and advancement for its young professionals by encouraging participation in professional association affairs, and assisting you to attend national meetings, seminars and conferences as well as visit other research facilities where related work is underway—government, uni- versity and industrial—throughout the United States. Liberal Personnel Policies, Attractive Location NSA policies relating to vacations, insurance and retirement are fair and liberal. You enjoy the benefits of Federal employment without the necessity of Civil Service certification. 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NSA's liberal graduate study program affords you the opportunity to pursue part-time study up to eight hours each semester and/or one semester or more CONTINUED FROM PACE 42 veloping series of terms. The 1/48=0.02 can be generated by a process reciprocal of 23 follows immed- 08 of continuous doubling: iately. 32 1/7 - 0.14 1/23 - 0.0432 128 28 256 512 56 2048 1024 112 (approximately) 16400 2048 224 4096 448 1/23 = 0.043478 8200 896 The convenient desk calculator 1/48^0.02083333333 1792 shows the answer: This results may be confirmed ' 3_5 4_8_ 1/23 = 0.04347828 l/48=(l/4) (1/12) =0.08333 .,„ 1/7-0.14285714285728.... We are doing all right now with 4 our ability to carry out such •0.020833... Why is this so? Upon further divisions to six places with a Notice how frequently two or reflection, we wonder why we minimum of mental effort. more of these methods are a- haven't tumbled upon this be- Let's try these methods on vailable in the attack upon any forel Notice that 7 goes into 100 an example from above. given problem. For example: fourteen times and leaves a re- 1/79 • 0.01 1/48=2/96 mainder of 21 It follows then 21 (The remainder is 21.) that 7 goes Into 200 twenty- nt\ ,v,n ( 441 (From FUN =2 (0.01+0.0004+0.000016 eight times and leaves aremain- 1 Approximation) Q 2 0 0 W 1 T H SQUARES) +0.00000064+...) der of 41 Similarly, 7 goes into (20 * 9200) 1 R4000 = 2(0.01041666...) 400 fifty-six times and leaves a =0.0208333... remainder of 8! This type of In- 1/79 ^ 0.01265 sight gives one a little of the Accurate calculation yields 1/77 = 0.01266, as we have seen. We The more you work with these feeling that Archimedes must methods in unison, the more have known when he discovered know, of course, that the an- swers derived by the series quickly you will see alternate in his bath that the volume of methods of solution. Since most an irregular solid could be de- method are small by virtue of the terms that should be included of the methods are mental, the termined by measuring its dis- mind tends to congratulate it- placement. on the right. There is little practical difference, however, in self upon getting the same an- the two answers above as ob- swer by two separate methods. But don't run shouting into the tained by two different methods. Your confidence in the methods street just yet. We have need to grows as you discover that you look further for the key to the Some practice examples fol- "know" a certain answer is cor- real utility of this discovery. low: rect, having "seen" it develop Take the example of the r e - 1/31 = 0.03 (remainder is 7) mentally by alternate methods. ciprocal of 23. We recognize 21 This is an example of the re- by Inspection that 23 goes into (these need not be 147 dundancy that space-age design- 100 four times and leaves a r e - labored over for 1029 mainder of 8. Therefore, 23 goes precision) 7200 ers try to build into their equip- into 800 thirty-two times and we • ment for added reliability. You 1/31 =0.03225801 " should practice redundancy, seek see that the remainder (which happens to be 64) is not im- The answer is correct through it, and use it, as a method of portant to us. All that we need seven decimal places. achieveing greater reliability in to do is to multiply 32 x 8 = The number need not be prime your work. When properly ap- 256 and then add it to the de- as have been used in the sev- plied by your mind, it takes. eral examples above. virtually no extra time. Cat research and engineering led the way to "Instant Evaluation" of Vehicles Test drivers could bounce across the field. really be speeded up. Why build a vehicle, But they couldn't remember every bounce. test it outside and make changes . . . if the Precise data was needed, on motion, vibra- concepted vehicle could be made to travel tion, balance, noise and seat position. Cat a "taped terrain"? engineers found a way. They used the analog computer, simu- First they had to develop instrumenta- lated a mathematical model and used a tion for recording all those effects on vehicle taped road profile as input data to the model operators. —with the computer output actuating the Then they developed a testing method ride simulator. Now, design modifications that would duplicate identical conditions in are pinpointed at once. Evaluations are a controlled lab environment. The Cat Ride made in moments, instead of days. Simulator. It has a ride platform with seat That's another example of what we mean and controls. A servo drive mechanism by new frontiers. If you'd like to help us which controls the platform. And an analog push back the boundaries of knowledge, we computer which directs the servo drive. need you. In research, development, design, That wasn't bad. They could tape verti- manufacture, sales. Here and overseas, cal acceleration measurements of a vehicle opportunities for Cat engineers—all fields- in the field. Then recreate them on the ride are endless. Platform. That let them study effects closely. Contact your placement office. We'll be And judge two versions of a vehicle in fast interviewing on your campus soon. Or write: quence—no human memory involved. College Recruiting, Personnel Development But there w e r e C a t e n g i n e e r s - T h e y w e n t Dept. B, Caterpillar Tractor Co., Peoria, 111. after the next step: evaluating prototypes P a p e r testing. If this with pre-hardware could be done, vehicle development could To Continue To Learn And Grow.. • . . . is a basic management philosophy at Delco Radio employes through the popular Tuition Refund Program. Division, General Motors Corporation. Since its in- College graduates will find exciting and challenging ception in 1936, Delco Radio has continually expanded programs in the development of germanium and silicon and improved its managerial skills, research facilities, devices, ferrites, solid state diffusion, creative packag- and scientific and engineering team. ing of semiconductor products, development of labora- At Delco Radio, the college graduate is encouraged tory equipment, reliability techniques, and applications to maintain and broaden his knowledge and skills and manufacturing engineering. through continued education. Toward this purpose, If your interests and qualifications lie in any of these Delco maintains a Tuition Refund Program. Designed areas, you're invited to write for our brochure detailing to fit the individual, the plan makes it possible for an the opportunities to share in forging the future of eligible employee to be reimbursed for tuition costs of electronics with this outstanding Delco-GM team. spare time courses studied at the university or college Watch for Delco interview dates on your campus, or level. Both Indiana University and Purdue University write to Mr. C. D. Longshore, Dept. 135A, Delc0 offer educational programs in Kokomo. In-plant gradu- Radio Division, General Motors Corporation, Kokomo, ate training programs are maintained through the off- Indiana. campus facilities of Purdue University and available to An equal opportunity employer If you still think glass is just glass, floor, maintain constant electrical properties at missile speeds, Ask about the Rover-B.R.M. 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(In the second ar- We want for intial conditions that tude at which Fd Is sufficient to r + i-0 at t = O. To solve this cause a d e c e l e r a t i o n of 1.0 ticle of this series we will ex- tend results obtained for a con- equation, it will be useful to make m e t e r / s e c * . (If the ship moves the following changes of vari- through the upper layers fairly stant-density atmosphere to real atmospheres of variable density.) able: (g - v2/r e ff) = G; (1/2PS1 rapidly. the total deceleration C D /M)=c2; f = d(f)/dt. Thus we p r o d u c e d by the layers above this The tangential acceleration a, or v, is the sum of the acceleration rewrite the equation as: upper limit will be negligible.) df We should expcct this upper limit due to drag forces and whatever acceleration there would be in (it = G - c2f 2 to be fairly c l o s e to the s u r - the absence of atmosphere. But Separating the variables and in- face: denoting the upper limit by we have seen that in the absence tegrating, ymax, we expectly max R. Thus in Ed. (4) we may set r • R .and of atmosphere we would have v = be quite close. Then, using F.qs. O. Consider the acceleration due (I) and (3) and letting M be the to drag forces. We combine Eq. C I is evaluated from the initial mans of the ship, the desired (5) with Newton's second law and, condition: y max can be found. There is no remembering that M is the mass 1 In S£ * cfn need to write an explicit equa- of the ship, we have cj = 2c \/G VG - cf0 tion, as this is Just one of sev- v • -F d /M • -U2(1/2PSCD/M) Let us introduce a new variable: eral criteria that could he used. where the minus sign indicates t' = t +Cj. Now we may solve the The important thing is that a that the direction of the force result of our first integration for reasonable value of ymax be used, is opposite in sense to the di- r: and used consistently In any par- rection of acceleration. JC e 2ct' yg - 1 ^ ticular problem. Let us solve this differential f : ? "2ct' Vn + 1 • c tanh In the absence of atmosphere, equation. We separate the vari- >/G ct (8) the orbit of the ship In the range ables and integrate: We could replace the new vari- below y m a x would be a conlcsec- -1/v = (-1/2PSC D /M)t +C ables c, G, and t' by the old var- tion. We may consider its motion 1 iables, but doing so would merely to be given by two parametric v = (l/2PSCo/M)t-f C complicate the equation. We may equations, with time as the para- Multiply top and bottom by Vj, integrate Eq. (8) now, subject to meter: r . r(t), 0 m 0(t). Let us the Initial velocity: the initial condition that r = consider the nature of these equa- vi ( R • Ymax) when t = O: r tions without actually performing v = (l/2vjPSCrj/M)t + C = (R *Ymax) -j-ln cosh ^Tct a parameterization. We know the We require the initial conditions range of r Is small-- from R to to be that v = vi at t = O. This This finishes our preliminary (R • v nMX ). Consider now Kep- allows us to evaluate the constant treatment of the motion of a ler's second law, which states: C: C = 1. Thus our final result spacecraft in an atmosphere. The For constant r, 0 « constant, is: final result we will want to con- where t> Is the ship's angular yj sider is that of the effect on a v c 1" >• i t v wit: t to the v • (l/2viPSCD/M)t + 1 (6) spacecraft's velocitv if It fires planet. From this it follows that We will perform another inte- retro-rockets. The differential for constant r, j» - O. Now in gration, but it will be convenient equation for velocity during re- fact r Is very nearly constant; to express the resulting equa- trofire is the following: the range of variation is small tion in terms of f>. We have v = v = -g + T _ in comparison to R and j?;=*O. ds/dt where s is distance along Mo - AVt If we take r to be constant, r = the orbit, but s • /Jreff. With this where T is the thrust of the r e f( s (R • l/2y r n a x ), then we can change of variable we may write retros, M o the spacecraft's mass take 1 ' O to a high degree of Eq. (6) as a differential equation at retro ignition, and M the rate accuracy. But jf - a/r, where a is and solve immediately. Our ini- of mass ejection by the retros. acceleration; hence in the ab- tial condition will be that at t =0 We solve this equation subject sence of atmosphere we may say we have 0 = f>0,