Write for your free copy of this vital reportImportant new information on the varied uses ofanalog computation in scientific education is nowavailable to all faculty members. This report tellswhy and how over 500 educational institutions aresuccessfully employing analog computers in educa-tion and research programs.Included in the report is a section describing actualapplications in engineering and science depart-ments, with comments by leading educators, de-

scriptive notes on analog computer fundamentalsand informative literature on the characteristics ofcomputers particularly appl icable to research, class-room instruction, and student laboratory use. Writefor your free copy of this report today.

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New circuits for communicationsThe success of a modern large-scale communications system depends importantly on the circuits of which it is built. For this reasonBell Telephone Laboratories places great emphasis on exploring new approaches to high-performance, economical circuit design.

The circuits illustrated below are but a few examples of recent Bell Laboratories Bell Telephone Laboratoriesdevelopments that are helping to advance the techniques of communications. Research and Development Unit of the Bell System

Circuit for mounting inside telephone hand-set for use by people with impaired hearing.Circuit includes one PNP transistor, pro-vides up to 25 db gain, and has negativefeedback for stability and to compensatefor variations in component characteristics.Power is derived by taking a small part ofdirect current supplied to the telephonetransmitter. Circuit board is flexible to per-mit part of conducting path to be bent andentire unit to fit snugly in narrow handset.

High-speed integrated logic package con-sists of 3 separate flip-flop circuits assem-bled together on a single header. On the11-lead ceramic header, all circuit inter-connections are made using gold thermo-compression bond wires. This device con-tains 6 transistors (2 are required for eachflip-flop) and 12 resistors. The individualflip-flops perform their switching functionswith typical operating times of approxi-mately 6 nanoseconds.

Parametric amplifier used in new micro-wave radio system will provide low-noiseamplification to a radio frequency signalwhich is frequency-modulated by 1200 tele-phone conversations. It is a reflection typeparametric amplifier operating in the 4-giga-cycle range, providing approximately 13 dbof gain using a varactor diode pumped atapproximately 12 gigacycles. Its very lownoise figure, typically 3.5 db, permits in-creased systems capabilities which are usedto increase the number of telephone chan-nels per radio channel.

Integrated balanced microwave amplifiermakes use of high-frequency germaniumtransistors for precise wideband applica-tions. Each stage of amplifier (one stageshown) consists of a pair of electricallysimilar transistors whose inputs and out-puts are combined by 3-db couplers. Thisarrangement eliminates tuning adjustmentsand provides excellent gain flatness andimpedance matching. Multistage amplifiersof this type have been designed to operatewith bandwidths of 1000 mc in the 0.5- to3-gigacycle range, with noise figures ofabout 6 db.

822

Compressor circuit used in several tele-phone carrier systems raises volume of softvoice sounds and lowers volume of loudvoice sounds. This new circuit effects a2-to-1 reduction in dynamic range of a tele-phone signal, which is then transmitted withan improved signal-to-noise ratio. Nearly per-fect compression is achieved over greaterthan the normal voice range, as a resultof circuitry that varies the impedance oftwo precise silicon diodes. A 3-stage feed-back transistor amplifier maintains desiredstability and provides the required trans-mission characteristics.

Thin-film decoder for high-speed pulsecode modulation systems converts binarypulse sequences into analog signals. Circuitconsists of precision resistor network andmultiply-encapsulated control diodes. Pre-cision resistors (pointer) generate referencecurrents that are switched into resistiveladder network (I-shaped elements at bot-tom of unit). Output voltage is proportionalto binary code applied to diodes. Precisionsufficient for decoding 9-digit binary codesis obtained, at code rates up to 12 mc.(108 mb/s pulse rates).

SCIENCE, VOL. 150

Report from

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It's a BeckmanCombinationElectrode withboth the pHelectrode and itsreference junction In thein a single shaft. space ofIt simplifies pH onedeterminations intest tubes and narrow-neckedflasks. You can work with samplesas small as 0.1 ml. Beckman.stocks eight different CombinationElectrodes. Others can bedesigned for unusual needs.Now you can get CombinationElectrodes in the Twin Pack. Askyour Beckman Sales Engineerabout this new, convenient wayto buy electrodes. Call him, orwrite for the Electrode Catalog.

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828

will speak to you about a greater art,that of cybernetics, which saves, notonly souls, but also bodies and pos-sessions, from the greatest dangers." Inthe Statesman (299b-c), the Strangersuggests to the Younger Socrates thata law be passed to prevent people from"persuading other younger men to es-say cybernetics and medicine not ac-cording to the laws." And in theCleitophon (408b), we find "the cyber-netics of men, as you, Socrates, oftencall politics."Many centuries later, the French

mathematician and physicist AndreMarie Ampere (1775-1836) employedthe word "cybernetics" in his greatEssai sur la philosophie des sciences(1834). By this, of course, Amperemeant only the "means of governing"people, not Wiener's important newscience.

PANos D. BARDISSocial Science, University of Toledo,Toledo, Ohio

Readers, Foreign and Domestic

In his letter about the readership ofContributions to Geology ("Who readsthe journals?", 17 Sept., p. 1325),R. B. Parker reports that "apparentlyour foreign readers outnumber thedomestic ones by a very large factor,"basing that conclusion on the fact that"we see references [to the journal] inmany foreign journals, and reprint re-quests from abroad are numerous."He goes on to say, "The fact thatmany such requests and references arefrom respected and influential scien-tists reflects discredit upon Americanscientists," and he suggests that Amer-ican scientists should "spend more timereading and less writing."One is tempted to ask: How many

journals has Parker canvassed in asearch for references to Contributionsto Geology? And in comparing reprintrequests, has he taken into account thatmany American scientists mail reprintsroutinely to their colleagues withoutwaiting for requests?

Having been associated with a per-haps similar publication (TulaneStudies in Zoology), I am aware ofthe tremendous response by institutionsin foreign countries to an offer toexchange journals. American journalsdo not, to my knowledge, make apractice of exchanging. Thus an equallyplausible explanation of the large num-

ber of foreign reprint requests maybe that the distribution system favors -them.

I object to the castigation of thereading habits of "American scientists"(presumably of all disciplines) on thebasis of an unsubstantiated opinionconcerning the reading of one journalprimarily of interest to scientists in asingle discipline. There may be sometruth to Parker's accusation, but it isnot supported by the statements in hisletter.

ROBERT K. CHIPMANUniversity of Vermont, Burlington

Parker concludes from the activeforeign readership of Contributions toGeology that "our colleagues in Europeand Asia are apparently vastly betterinformed than we are." I should liketo suggest that exactly the reverse maybe indicated. For most scientists seri-ous reading represents an acknowledge-ment of the need to be informed. Thosescientists who are geographically far-thest removed from personal contactswith fellow specialists are quite likelyto feel the greatest need for journals. sIt does not necessarily follow that theywill become the best informed. Per-sonal observation leads me to the op-posite conclusion-that the man whois best informed relies least upon thejournals for enlightenment. He isserved by a number of other commun-ication channels-personal contacts,conferences, correspondence, preprints-most of them considerably fasterand more efficient. There may even,be a continuous negative correlationacross the spectrum of informedness,leading finally to the nervous neophytewho reads all the journals for fear ofmissing something.

VANCE WEAVER2465 Broadway, New York 10025

. . . I should like to ask Parker whyhe felt it necessary to start yet anotherjournal. I submit that American sci-entists do read worth-while journals,but that most of them, like me, havemore and more difficulty readingthrough more and more publicationsto separate the mass of trivia from othe relatively few significant contribu-tions to scientific knowledge.

JOHN HELWIG, JR.Cardiovascular Section,Germantown Hospital,Philadelphia, Pennsylvania 19144

SCIENCE, VOL. 150

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8-10. New Concepts in GynecologicalOncology, symp., Hahnemann Medical tCollege and Hospital, Philadelphia, Pa.

SCIENCE, VOL. 156

NEWRUSSIAN ATLASImported from U.S.S.R.

FIZICO-GEOGRAPHICHE-SKII ATLAS MIRA

This Atlas consists of 3 sections:1. Maps of the World2. Maps of the Continents3. Maps of the U.S.S.R.

Each section contains information onorography, geology, tectonics, minerals,quarternary sedimentation, physiography,climate, soil, flora and fauna, and physio-geographic regions. Also included is de-scriptive text in Russian. There are 241maps. Map scales vary from 1/15 000 000to 1/150 000 000. Size 32 x 50 cm.

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LATEST SCIENTIFICINFORMATION FROM U.S.S.R.Write for complete 1966 catalog. ListsRussian scientific magazines, journals andperiodicals in your field.

FOUR CONTINENT BOOK CORP.Dept. 624, 156 FIFTH AVE., N.Y., N.Y. 10010

2-3. Bone Marrow, conf., San Francisco,Calif. (L. J. Cole, Experimental PathologyBranch, U.S. Naval Radiological DefenseLaboratory, Hunter Point, San Francisco94135)

2-3. Society of Plastics Engineers, re-gional technical conf., Newark, N.J. (SPE,65 Prospect St., Stamford, Conn. 06902)

3-5. Leptospiras, intern. colloquium.,Antwerp, Belgium. (A. Grare, lnst. deMedicine, Tropicale Prince-Leopold, Ant-werp)

3-5. Academy of Psychoanalysis, mid-winter meeting, New York, N.Y. (H.Davidman, 125 E. 65 St., New York10021)

3-5. American Psychoanalytic Assoc.,fall meeting, New York, N.Y. (APA, lE. 57 St., New York 10022)

3-4. Macromolecular Metabolism,symp., New York. N.Y. (New York HeartAssoc., 10 ColurmbuLs Circle, New York10019)

5. Americaln Acad. of Dental Medicine,mid-winter annLual meeting, New York,N.Y. (S. Conrad, 133-28 228th St., Laurel-ton, N.Y. 11413)

5-9. Ameirican Inst. of Chemical Engi-neers. Philadelphia, Pa. (AICE, 345 E.47 St., New Yorki 10017)

5-11. American Rheumnatism Assoc.,congr., Mar del Plata, Argentina. (G.Speyer, 10 Columbus Circle, New York)

6. Food Law Inst. and Food and DrugAdministration, joint educational conf.,Washington, D.C. (FDA, Washington,D.C.)

6-7. Medical and Social Aspects ofMigration, Ciba Foundation guest symp.,London, England. (Ciba, 41 Portland P1.,London, W. 1)

6-8. Transmission of Viruses by theWater Route, symp., Cincinnati, Ohio.(G. Berg, U.S. Public Health Service,'4676 Columbia Parkway, Cincinnati45226)6- 0. Space Communication, Paris,

France. (UNESCO, P1. de Fontenoy, Paris7')

6-10. Practices in the Treatment of Lowand Intermediate Level RadioactiveWastes, symp., Vienna, Austria. (Intern.Atomic Energy Agency, Kiirtner Ring 11,Vienna 1)

6-10. Structure and Function of theNuclelolus, symp., Montevideo, Uruguay.(F. A. Saez. Instituto de Investigacionesde Ciencias Biologicas, avda. Italia 3318,Montevideo)

6-12. Hydraulics and Fluid Mechanics,2nd Australasian conf., Auckland, NewZealand. (A. J. Raudkivi, Univ. of Auck-land, School of Engineering, Ardmore Col-lege Post Office. Auckland)

7-10. American Soc. of AgriculturalEngineers, winter meeting, Chicago, I11.(J. L. Butt, P.O. Box 229, St. Joseph,Mich.)

8-10. Coccidioidomycosis, 2nd natl.symp., Phoenix, Ariz. (Arizona Tubercu-losis and Health Assoc., 733 W. McDowellRd., Phoenix 85007)

8-10. Changing Concepts of HumanHabitation, symp., Roorkee, India. (D.

I

(Miss S. Rosen, Hahnemann Medical Col-lege and Hospital, 230 N. Broad St., Phila--delphia 19102)

8-15. American Acad. of Optometry,Chicago, Ill. (C. C. Koch, 1506 FoshayTower, Minneapolis, Minn.)

9-10. Ciba Foundation guest meetingEuropean Pancreatic Club. London, Eng-land. (H. T. Howat, 41 Portland P1., Lon-don, W. 1)

12-14. Lymphatic System, intern. conf.,New Orleans, La. (H. S. Mayerson, Dept.of Physiology, School of Medicine, TulaneUniv., New Orleans 70112)

13-15. Aerothermochemistry of Turbu-lent Flows, conf., American Inst. of Aero-nautics and Astronautics, San Diego. Calif.(H. Yoshihara, Space Sciences Laboratory,Mail Zone, 596-00, General Dynamics/Astronautics, Kearny Villa Rd., San Diego)

13-15. European Biological Editors,Paris, France. (D. S. Ferner, Dept. ofBiology, Univ. of Washington, Seattle)

13-15. Radiological Protection in theIndustrial Use of Radioisotopes, intern.conf., Paris, France. (J Pradel, 66 rue Au-gustin Dumont, Malakoff, Seine, France)

13-18. Engineering and TechnologicalSciences, conf., Bangkok, Thailand. (P.

* Purachatra, Assoc. of Soiutheast AsianInsts. of Higher Learning, ChulalongkornUniv., Race Course Rd., Bangkok)

15-18. Microbiology, 1st Central Amer-ican congr., Univ. of Costa Rica, San Jose.(F. Montero-Gei, School of Microbiology,Univ. of Costa Rica, Apartado 2157, San

, Jose )19-21. Middle East Neurological Soc.,

Jerusalem, Jordan. (F. S. Haddad, OrientHospital, Beirut, Lebanon)

19-23. Indian Statistical Inst., Malles-waram, Bangalore. (S. R. Ranganathan,Indian Statistical Inst., Documentation Re-

4 search and Training Centre, 112 CrossRd. 11, Malleswaram)

20-21. Nuclear Medicine, 2nd natl.congr., Tel Aviv, Israel. (P. Czerniak,Israel Atomic Commission, Soreq NuclearResearch Center, Doar Yavne)

20-22. British Biophysical Soc., 20thwinter meeting, London, England. (R. E.Burge, Physics Dept., Queen ElizabethCollege, Campden Hill Rd., London W.8)

20-22. American Physical Soc., LosAngeles, Calif. (W. Whaling, CaliforniaInst. of Technology, Pasadena 91109)

26-31. American Assoc. for the Ad-vancement of Science, annual, Berkeley,Calif. (R. L. Taylor, AAAS, 1515 Massa-chusetts Ave., NW, Washington, D.C.)

In addition to the 20 sections of theAssociation and five AAAS committees,the following organizations have arrangedsessions at AAAS annual meeting 26-31December in Berkeley:

MathematicsAmerican Mathematical Soc. (R. S.

Pierce, Univ. of Washington, Seattle)Association for Computing Machinery.

(H. D. Huskey, Univ. of California,Berkeley)

National Council of Teachers ofMathematics. (J. D. Gates, 1201 16 St.,NW, Washington, D.C.)

Society for Industrial and Applied Math-, ematics (J. H. Griesmer, IBM, Yorktown

Heights, N.Y.)12 NOVEMBER 1965

Here's a Tekfronix oscilloscope features: crt with an internalfeaturing operational simplicity graticule and controllable edgeandversatilitythroughanewseries lighting * regulated power sup-of plug-in units. Presently,you can plies * regulated dc heater sup-selectfrom 17 amplifier units and 7 ply * Z-axis input * 3.5-kVtime-base units. Plug-in units offer accelerating potential * ampli-capabilities from 100 MuV/cm sen- tude calibrator * and operationsitivity (3A3) and 10 MHz pass- from 105 V to 125 V or 210 V to 250band (3A1, 3A6), to 0.5 ,usec/cm V, 50-400 hertz. (Type RM561Asweep rate (3B1, 3B3) and sweep- operates from 50-60 hertz.)delay applications (3B1, 3B2, 3B3). Type 561A Oscilloscope . . . $500

Knowing yourapplication area, youselect units to fit your needs. Withany combination of plug-ins-in-cluding the same type amplifierunits in both channels for X-Y dis-plays-this oscilloscope providesyou with "no-parallax" displays foraccurate, reliable measurements.

Type RM561A Oscilloscope. . $550Occupies only 7 inches of standardrack height.

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IINSTRUMENTS, INC.

SCIENTIFIC AND PROCESSINSTRUMENTS DIVISIONFULLERTON, CAUFORNIA . 92634

uTERNATIONAL SUBSIDIARIES: GENEVA, SWITZERLAND;MUNICH, GERMANY; GLENROTHES, SCOTLAND; PARIS,FRANCE; TOKYO, JAPAN; CAPETOWN, SOUTH AFRICA

932

PhysicsAmerican Astronautical Soc. (P. B.

Richards, General Precision, Little Falls,N.J.)

ChemistryAmerican Chemical Soc., California Sec-

tion. (R. L. LeTourneau, Chevron Re-search Co., Richmond, Calif.)

AstronomyAmerican Astronomical Soc. (G. C.

McVittie, Univ. of Illinois, Urbana)Geology and Geography

Association of American Geographers.(M. Mikesell, Univ. of Chicago, Chicago,Ill.)

National Geographic Soc. (R. Gray,17th & M Sts., NW, Washington, D.C.)

National Speleological Soc. (G. W.Moore, U.S. Geological Survey, MenloPark, Calif.)

Zoological SciencesAmerican Fisheries Soc. (H. K. Chad-

wick, California Dept. of Fish and Game,Sacramento)

American Soc. of Zoologists. (A. G.Richards, Univ. of Minnesota, St. Paul)

Animal Behavior Soc. (E. M. Banks,Univ. of Illinois, Urbana)

Herpetologists' League. (F. B. Turner,Univ. of California, Los Angeles)

Society of Systematic Zoology. (J. G.Rozen, Jr., American Museum of NaturalHistory New York, N.Y.)

Zoological and Botanical SciencesAmerican Soc. of Naturalists. (C.

Hubbs, Scripps Inst. of Oceanography, LaJolla, Calif.)

Ecological Soc. of America. (G. M.Woodwell, Brookhaven Natl. Laboratory,Upton, L.I., N.Y.)

Western Soc. of Naturalists. (J. M.Craig, San Jose State College, San Jose,Calif.)

PsychologyWestern Psychological Assoc. (G. A.

Mendelsohn, Univ. of California, Berkeley)Social and Economic Sciences

American Economic Assoc. (R. R. Nel-son, RAND Corp., Santa Monica, Calif.)American Political Science Assoc. (J.

F. Triska, Stanford Univ., Stanford, Calif.)American Soc. of Criminology. (C. New-

man, Univ. of Louisville, Louisville, Ky.)American Sociological Assoc. (W. Form,

Michigan State Univ., East Lansing)Metric Assoc. (R. Fischelis, Ohio North-

ern Univ., Ada)National Inst. of Social and Behavioral

Science. (D. P. Ray, 863 Benjamin Frank-lin Station, Washington, D.C.)

Population Assoc. of America. (E. S.Lee, Univ. of Pennsylvania, Philadelphia)

Society for the Scientific Study of Re-ligion. (C. Y. Glock, Univ. of California,Berkeley)

History and Philosophy of SciencePhilosophy of Science Assoc. (C. W.

Churchman, Univ. of California, Berkeley)Society for General Systems Research.

(H. Thal-Larsen, Univ. of California,Berkeley)

Science Courses for Baccalaures -cation Project. (V. L. Parsegiat, Am-selaer Polytechnic Inst., Troy, N.Y.)

Medical SciencesAlpha Epsilon Delta. (M. L. Moore, 7

Brookside Circle, Bronxville, N.Y.)American Assoc. of Bioanalysts, West-

ern Region. (M. Menesini, 1287 RudgearRd., Walnut Creek, Calif.)American Physiological Soc. (R. M.

Iverson, Univ. of Miami, Coral Gables,Fla.)American Soc. for Microbiology, North-

ern California-Hawaiian Branch. (K. J.Taylor, Cutter Laboratories, Berkeley,Calif.)

California Veterinary Medical Assoc.(A. G. Edward, Univ. of California, Davis)

Society for Experimental Biology andMedicine, Pacific Coast Section. (E. L.Dobson, Donner Laboratories, Univ. ofCalifornia, Berkeley)

EducationCommission on Science Education. (J.

R. Mayor, AAAS, 1515 MasshusettsAve., NW, Washington, D.C. 20005)

American Nature Study Soc. (H. E.Weaver, Univ. of Illinois, Urbana)

National Assoc. for Research in ScienceTeaching. (F. B. Dutton, Michigan StateUniv., East Lansing)

National Assoc. of Biology Teachers.(H. K. Wong, Menlo-Atherton HighSchool, Atherton, Calif.)

National Science Teachers Assoc. (A. F.Eiss, 1201 16 St., NW, Washington, D.C.20005)

Information and Communica6miNational Assoc. of Science Writers. (L.

S. Zahn, Hill and Knowlton Inc., 150 E.42 St., New York, N.Y.)

Society of Technical Writers and Pub-lishers. (G. Marx, Illinois Inst. of Tech-nology, Chicago)

StatisticsBIO: Biomedical Information-Processing

Organization. (M. Woodbury, New YorkUniv. Medical Center, New York, N.Y.)

Biometric Soc., ENAR. (D. S. Robson,Cornell Univ., Ithaca, N.Y.)

Biometric Soc., WNAR. (S. W. Nash,Univ. of British Columbia, Vancouver,Canada)

Mathematical Statistics and Probability,5th Berkeley symp. (J. Neyman, StatisticalLaboratory, Univ. of California, Berkeley)

p

Science in GeneralAcademy Conf. (J. T. Self, Univ. of

Oklahoma, Norman)Scientific Research Soc. of America (D. ,

B. Prentice, 51 Prospect St., New Haven,Conn.)

Sigma Delta Epsilon. (Miss A. Hanson,Univ. of Minnesota, Minneapolis)

Society of the Sigma Xi. (T. T. Holme,51 Prospect St., New Haven, Conn.)

27-29. Academy of Managen-. NewYork, N.Y. (P. P. LeBreton, Coleip ofBusiness Administration, Univ. of Wash-ington, Seattle)

27-30. Differential Equations mm Dy-namical Systems. Univ. of Puerto Rico,Mayaguez. (Center for Dynamical Systems,Brown Univ., Providence, R.I.)

SCIENCE, V. t*

*T14