NEWENZYM EPREPARATIONS by

wortIlIj gton

1. ALKALINEPHOSPHATASE (BACTERIAL)A phosphomonoesterose with a pH optimumof 8.0 and an unusual thermal stability.This highly purified enzyme is preparedby methods based on the following work:1. Torriani, A. Biochimica et

Biophysica Acta. (In press)

2. Garen, A. and Levinthal, C. (Ibid)

2. YAMINO BUTYRATEGLUTAMATE TRANSAMINASESUCCINIC SEMIALDEHYDEDEHYDROGENASEA coupled enzyme preparation for therapid spectro-photometric assay of-y amino butyrate (GABA), a compound of(onsiderable current interest in the fieldof brain metobolism.

The preparation and method of y aminobutyrate analysis are based on thefollowing work:

1. Scott, E.M. and Jacoby, W. B.,National Institute of Arthritis andMetabolic Diseases. Journal of

Biological Chemistry, 234, No. 4,932 (11959)

2. Jacoby, W. B. and Scott, E. M.,Journal of Biological Chemistry, 234,No. 4, 937 (1959)

Write for information:

TU11682

LettersOn the Origin of Life

Nillnx papers have appeared in re-cent xears. sexeral in Science, on thetopic of the origin of life. I have beensomexx hat disturbed to note the ever-incre,asing tendencx, especilly amongbiochemlists. to identity the event ofthe oricin of life xxith that of the oricinol' enzx mnes or of deoxxribonucleic acid.It appears to m1e thatt ouLr greativ in-creased rate of discovery of facts per-taininme to the chcmistrx of hereditalrxmechanlisllls and the relationship ofcnrz mne constituition to genotvpe has ledto al distortioni ol' the basic problem .andmislcd manx into this identificationl.

I dlo not propose to enter here into aidi.SCLSsiOnl of the problemii of the oricinof lixiuc, sxstems and the possible importance of cxclic factors. x Thich I hax etrealtetd elsexhere [Am-. Alaottrli[xt 81.6 ( l947)]. buLt shouLlcd likc. rather.

to prcscnt atn lanalogy xwhich mnax' serx\eto make mx point.

Consider the probleimi of the oricin offar-l1lune2 industria.il corporations. Tothe ulntrincd observer the probleml ot'the origin of sLuch structures might per-hallps resolxe itself into thalt of theorigiln of corporaltion buildings. maL-chinerv. raxw materials. calpital. xorkers.salles oLItlets. and so on. The tralinedobserver xould seek his ansxx er in astud& of the history of corporations.Hc \\ oul_d correctlx conclude that thecorporate gilnt often derives froll] thehumliible garace or basement xxworkshopin xwhich the inventor experinments inhis ofl houirs to decelop a nexx produLIctor process. He x ould then trace thesiox process of corporate Cx olUtionthrouLh the small shop of t\xxo or threeemployees. to the modlest factorx. tothe giant f actorx, to manyx '.fctories.atidcT so onl aid on to the indLustrial comil-pIles x ith its directiuc board and manxstockholders.

I et Lus sUppOSe that xxe cal 110o moIctrace the historx of corporations thanxe czian directl! trace the historx oflit'c. The trLilled obserxver night insteadInsInu-LatC himisell' into the inner xx ork-ings ot' the corpor.ition unltil he breachedthe inner sanctum the board of dlirec-tors. He xould then discover that theboard otf directors is the kc stone ot'corporate policy aund action.l arxincthe compalnx program. produLIct Cilm-phasis. and ex en the corporate strLuc-tuLre in responise to changing economlicconditions and opportuLnities. electingthe officers xxho see to the fine detailsof operation, ancd so on, and, indeed,that every action of the corporate enter-prise traces directly or indirectly to themake-up and actions of the boardcto

the corporate DNA. In his new fa-miliarity with the manifold operationsof the all-poxerfUl board and the con-sequences of these operations, the SolI-tioln to the problem of the origin otcorporaitions might suddenly comle uponhiml; daIzzled by his suLddenly acquiredknoxxledge, he might conclude hastilvthat the problemii of the origin of corpo-raitions WxLas to be identified with theprobleml of the origin of boards otdIi rcctors!

J. LEE KAVANA\LDc/poartenct (of Zoolo)gy,1Ljniverxsitv of Califorilia, Lo.v A. it'Jeles

Linear and Higher-Order Curves

In Fig. ot the article "Investiga-tiolns of natUral environmental radia-tion' [Science 131, 903 (1960)] by L.R. Solon ei a!., there is presented astraight-l ine regression on the rclation-ship bet een harometric pressure andthe log of raliation level. Even acasalI inspectioni of this graph indi-caItes thait ai better emnpiric,ail descrip-tionl \xould be aiven by a second-degreeculrx e. This may be inferred from thesystematic deviationi ot' the observedpoints I'roml the fitted line.

,s a simiple description of the re-litionship xx ithin the range of observa-tionS. it x ould nmake little difference,bLit since this line is used for cxtrapola-tion. consi'derable error miay, result. Forcxample. the 3.8 p1r/hr extrapolation forcosilulc-ray ionizatioll intensity at sealexel for Nexx York City nmight resultin .in estimate ot' 5 r/ hr (or a difTer-cnce of about 33 percent) if a curvedline xwere uised.

NIARVIN GL ASSER44 Bitsiie!/l St-eut.Bowoi,i. Masschicii,etx s

In his letter M/arxin Glasser sugIgeststhat aibetter fit to the cdat in Fig. Iof' ouir article could hav,,e been achievedbx using a higher-order polxNnomial thanthe linear regression exhibited.

I a(ree thait a- quadratic or higher-dearee poIN nomial x oulld constitute acloser fit to the empiric,al clata. (In falct.since the cCUrxe is basedl on 19 experi-mlentaLl points, an 8-legree polynomiale\ists xhich xxou0l1d fit the dlata perfect-lx'8)

I disalgrec thatt using a hig,her-deg,reepolxnomial xW ould result in a curve thatxWould he better for extrapolation.

Further, I submit that if a set of emi]-pirical points actually obey a linear law,anx higher-degree curves whether theN,fit the data,1 better or not almost cer-talinlv xxould be wvorse for extrapola-tion. Extrapolation of such a linear rc-lationship depends simply on the slopc

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of the regression line. If extrapolationf'roml the higher-degree curve outsidethe emnpirical range gave the same nu-merical result ,as a linear least-squLaresfit, it xvould mlerely be fortuitous.The linea.r fit is especially suitable for

our airplane dtma. It corresponds physi-cally to an exponential attenuationmechanism wvell established in cosmilicradiation-absorption processes. A quad-ratic (or higher-degree) fit would not bejustified by the physics of the situation.

LEONARD R. SOLONHe iltli andi(l SafetY Laboratory,Ne.is Yor-k O rotio,i. Office, A t(onicEneri v Comzi.;s-ion, News Y'ork, N.Y.

Types and Name-Bearers

Shenefelt [Science 130, 331 (1959]has suggested that proposal of a nexNspecies should be prinmarily by descrip-tion of a single specimien, the type(Tholotype'). Schopf [Scienice 131,1043 1960)1 hais objected, mainly onthese grounds: types are not typical:description of a specimen does not de-scribe or define a species: and theproper function of a type ("holotypel.)is solely that ot name-bearina. I entire-lv agree \vith Schopf, and I m1ade thesame points at greater length 20 years

ago [A,ui. J. Sci. 238, 413 (1940)].Since then this attitude has becormie'sidespread but, as Shenefelt's noteshows. not universal.

Schopt' proposes that a type as name-bearer be called 'nonmenifer." The com-bining form1 of nomnenIsis ntinin-, andthe word should theret'ore be nominnifer.

Ilong since proposed the Greek-derivedequivalent onopn-atophlore. There is noparticular reason to prefer Greek orI atin derivation. but current type terni-nologv is derived fronm Greek.

I do not mysc If regularlv use thetermi onmomaitophore, and I do not knoiwof anvone wxho does. Nomninifer is notlikelv to tare better. The term1 tYpe. xwithall its confusing connotations, is toostrongly entrenchecd in taxonomy. Codesof nomiienclatuLre require designation ofty pes. under that name, and there islittle or no chance of eradicating thatusasze.The onoma-itophore or nonminifer is

the type of m1odern talxonomiiy. Addition-a] designations such as holotvpe a,Lndparaltype only perpetuLate the idea thalttypes can serve other than nomlenclatuLtr-a1l funLctions aind hence can be of mlorethan one kind.

G. G. SIMPSONAli.acitin of Comparative Zoolo(.'v,Hal arcrd Uniiv-er sity,Cambnzhrid-'e, Ala s(laclhusetts

MeetiilgsNeuropathology

The Coinimissioni for NeuropathologyWx as fouLnded by invitation in the Sal-petricre Hospital in Paris on 24 Octo-ber 1959. At this meeting were presentLuLdo van Bogaert and Pearce Bailey,presidlent and secretary-general, respec-tixelv. of the World Federation of Neu-rology.

The follow ing netLropathologists hadlbeeni invitedl and became charter nmemii-bers ot' this conmnmission: J. Bertrand(France): E. Christensen ( Denmnark):P. B. Diezel (Germanv ): WV. Girard(Fra.nce): WV. Ha nmaker ( UnitedStiates): A. C. Loken (Norxva1v): F.L Lithx (Svvitzerland) : WV. H. NlcMene-mev ( Great Britain ): E. OsetowskaPoland ) : G. Peters ('Germanv ). who

W aS Unable to attend the meeting: F.Seitelberger (AAustria): P. Sourander(Ssweden); J. 0. Trelles (Peru); andXV. J. C. Verhaart (Netherlands).

F. Seitelberger wx as elected secretaryof' the conmm1ission. The permanent sec-retariat has its headquarters at the In-stitute of Neurology of the Universitvof ViennL ( Obersteiner Ilnstitut)Schxvarzspaniei-strasse 1 7. VCen1na 9.AuLstrial.

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Recent experiments at the METROHM laboratories inHerisau, Switzerland produced a major breakthrough tothe "time problem" - Rapid DC Polarography. With thismethod the mercury drops of an otherwise normal droppingcapillary are mechanically induced to fall at a muchfaster rate. Consequently, artificial drop signals measuredin tenths of seconds are obtained. Since a considerablygreater number of individual drops are utilized, one canalso increase the speed of the potential change. The normalrunning time in Rapid Polarography is 50 seconds. With adrop interval of 0.2 seconds there are 250 drops on thepolarogram. To obtain the same number of measuring pointswith the standard method would require a running timein excess of 12 minutes for a drop interval of 3.0 seconds.SEND FOR COMPLETE DESCRIPTIVE CATALOG TH 25

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6" x 9", 424 pp., 37 illtis.. index, cloth.Price $9.00, AAAS memiibers' cash or-ders $8.00. AAAS Symposium VolumeNo. 53.

This volume is intended as a review ofknow ledge on many aspects of grass-laLnds resouLrces. The 44 aithors wereselectecd by thcir ow n professional col-leagLiS as being particiularly comlpetentto pIc-sent the respective sulbhjects.Thirtxt-sexen papers are arranged underthese chapter headings:1. Sciences in SuLpport of Grassland

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The commission claims independencefor neuropathology as a proper niedicaldiscipline and emphasizes the necessityof independent positions for full-timeneuropathologists. Therefore the com-mission will examine the situation ofneuropathology and neuropathologistsin various countries and consider fur-ther action for protecting the neuro-pathologist's basic interests. In interna-tional congresses of the various neuro-logical disciplines, the competence ofneuropathology is to be recognized inan appropriate way.

NMoreover the conmmission will be in-terested in preserving and caring forthe valuable neuropathological collec-tions in variouLs places. It will try tomnake it possible for all interested scien-tists to use these collections.One of the main tasks of the com-

mlission will be that of effectively pro-mloting scientific activities in the fieldof neuropathology. For that purpose itis proposed that information be ex-chang,ed and personal contacts be ar-ranged wsithin the fieldl of neuropathol-ogy and between neuropathology andrelated andl basic scientific disciplines todevelop suitable mlethods of investig-a-tion.

Finallyv the coimmission is to be aconsultative instrutmient within theWorld Federation of Neurology forexanmple. to promlote imiiportant projectsof nxvestigation.

After a thorough discussion it wasdecidled that an international journal ofneuropathology should be published,to be issued in several ]anguages.

The secretary of the Commllission ofNeuropathology will endeavor to keepthe various medical journals informedabout the activities of the conmmission.He welcomes all relevant suggestionsfrom his colleagues interested in thisproject.

F. SEITELBERGERObersteitner Ii stitl(t, Vieninia, A istria

Forthcoming EventsJune

22-25. Society of NuLclear Medicine,Estes Park, Colo. (T. P. Sears, V.A. Hos-pital, Denver 20, Colo.)

25-5. First Intern. Cong. on AuitomaticControl, Mloscow. U.S.S.R. (R. Olden-bturger, Mechanical Engineering Dept.,PurduLe Univ.. Lafayette. Ind.)

26-1. American Physical TherapyAssoc.. IittsbuLrghi, Pa. (Miss J. Bailey, 157N. 79 St., MilwaLikee 13. Wis.)

26-I. American Soc. for Testing Ma-terials. Atlantic City, N.J. (R. J. Painter,1916 Race St., Philadelphia 3. Pa.)26-1. Mass Spectrometry, 8th annual,

Atlantic City. N.J. (V. H. Dibeler, NationalBureaul of Standards. Washington 25)

26-1. National Education Assoc., LosAngeles, Calif. (W. G. Carr, 1201 16 St.,NW, Washington 6)

26-2. American Physical TherapyAssoc., Pittsburgh. Pa. (Miss L. Blair, 1790Broadway, New York 19)

27-29. Mlilitary Electronics, 4th natl.conv., Washington, D.C. (C. M. Crensha.v,Dept. of Army, Office of the Chief SignalOfficer, R. & D. Division, SIGRD-2, Wash-ington 25)27-29. StatuLs of Problems of Molecular

Structure, symp., Seattle, Wash. (P. C.Cross. Dept. of Chemistry, Univ. of Wash-ington. Seattle 5)

27-30. Coherence Pr-operties of Elec-tromagnetic Radiation. conf. (by invital-tion). Rochester. N.Y. (E. Wolf. OpticsInstitLite. Rochcster Univ.. Rochester)

27-30. Instittute of the AeronaLutical Sci-ences. Los Angeles. Calif. (R. R. Dextei.IAS. 2 E. 64 St.. New' York 21)

27-30. National Assoc. of Power Engi-neers ainnuLal conv.. San Francisco, Calif.(E. J. SchuLetz. NAPE. 176 W. Adams St..Chlicaio 3. 111.)

27-1. Internatioinal Assoc. for Brid-cand Sti uctuLral Engineering, 6th cong..Stockholmn. Sweden. (P. Lardv. IABSF.Ecole Pol ytcchnIique Federale, ZuLrichSwNitzerland)

27-1. Rcading Couf.. 2nd annual. Syra-cutse. N.Y. (R. A. Kress. Readling Centei-.SyracLuse UJniv.. Syraculse10)

28- 1. American Home EconomicsAssoc.. Denver. Colo. (Nliss NI. A. Warren.School of Home FIconomics, Univ. ofOklahornmal. Norman)

29-1. Health Phxsics Soc.. 5th annuall.Boston. NMass. (E. E. Andei-son. HealthPhx7sics Div.. Oak Ridge National Laboi-a-tory. Oalik Ridge. Tenn.)

July3-5. American Assoc. of Colleges of

Pharmacy, Boulder-. Colo. (G. I. Webster.College of Pharmacy Unix. of Illinois.Chicago 12)

4-8. Polarization Phenomena of Nudce-ons, symp., Basle, Switzerland. (K. P.Meyer, Physikalisches Institut der Uni-versitait Basle. Klingelbergstr. 82. Basle)

5-9. Goiter Conf., 4th intern., London,England. (J. C. McClintock, 1491/2 Wash-ington Ave.. Albanv 10. N.Y.)

6-15. Entomological Conf.. 7th Com-monwveialth, London, England. (Common-wealth Inst. of Entomology, 56 Queen'sGate. London. S.W.7)

10--14. Pan American Tubei-culosisCong.. 12th, Bahia, Brazil. (F. D. G6mez,26, de Marzo, 1065, Mlontevideo, Uru-guLiaN' )

11-12. Response of Materials to HighVelocity Deformation, conf.. Estes Park.Colo. (AIME. 29 W. 39 St., NexsYoi-k 18)

11-15. British Dental Assoc., annual,Edinburgh, Scotland. (Secretary, BritishDental Assoc., 13 Hill St., Berkeley Sq.,London. W.I. Englanid)

11-15. Royal Medico-Physiological As-soc., anntual, London, England. (A. B.Monro, 11 Chandos St., Cavendish Sq..London, W. 1)

11-16. Inter-American Nuclear EnergyCommission, 2nd meeting, Petropolis, Riode Janeiro, Brazil. (J. D. Perkinson, Jr..Inter-American Nuclear Energy Commis-sion, c/o Pan American Union, Washing-ton 6)(See issue of 20 May for comnprehensive list)

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t onic M\arkintr l)robc; A Plug-in N\tarking Greatse1'enicil or Plug-in Matrkinc, Pein; ad a PLshbUttolnCotniter.C(olonies alre acctii ately recor(le(l in as-isile( 1)1r-Hl gtaction that leax-es in id(enltilyving punctul(ttllre Hnrhie a-gar. Th'lie Electroniic l1rob)e picks ti" ri(li)o illl--pIuScs o0i contact with )1(tlragr lne(litiIll iti a(i;w-lT[ltes the countill- me1 bacImnism. Electrical splat-lering s corni:letely e1iiininatedl by the low voltage

iPlUllt. AVhere ptno 1tin2 is untleslirale, the Pitngin Grerase Peicil or iatrking Plen is uise(d to nmrkthe Ib;tck of the pltte tas it couNEWts.Platesate flooed withi brilliant whiite lighTt tha1tis cool, soft and easy oil the eyes. Specimens areillumlinated in bold reilief aga~inst at contra-stingo;igar batckgrotund, revealing colony morphology.Even pinpjoinit colon-ies a-re eatsi lv cliscernie(l.Th'le instrumiient has anl automahtiC numiierical re- WRITE FOR NEW BRset to zero, a sterilizinig l1robe \Vell anid a ma~gni- CATALOG a

fy,ing lenis. ClI 1O-63S p( r

UNCONDITIONAL1 YEAR WARRANTY

tUNSWICK SCIENTIFIC CO.

606. NEW BRUNSWICK, NEW JERSEY

3~~~ JUN 19018

I

, II I I-1:1:11 L11-

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r.v. t5 UA

3 JUNE 1960 1687

EPIDEMIOLOGYOF MENTAL DISORDER

AAAS SymposiumVolume No. 60

Edited by Benjamin Pasamanick

A symposiumL1 orgaanized by theAnmerican Psvchiatric Associa-tioIn to conmmemorate the cenlten-nial of the birth of Emil Kraepe-lin; cosponsored by the AmericanPublic Health Association.

. . . pioneeringc interdisciplinarystudies by investigators from bio-statistics, genetics, obstetrics, pe-diatrics, psychiatry, psychology,public health and sociology.

Decemiiber 1959, 306 pp., $6.50AAAS mlemiibers cash orders, $5.7 5English Agents: Bailey Bros. & Swinfen, Ltd.

West Central StreetLondon W.C.1, England

American Associationfor the Advancement of

Science1515 Massachusetts Ave., NW

Washington 5, D.C.

Try UNITRON'S new

MICOSOP

The Model MPS is a precision instro-cent designed to meet the exactingrnquiiremenits ot science, educationand industry. Ideal ton work in chemis-try,crystallography, biolcgy. as well anthe technology nt paper, glass, teotilesand petroleum.

.Eyepieces: 5X (micro.), IOX (cross.Objectives: 4X. IOX, 41X, achro-matic, strain-tree, centerableNosepiece: quick-change typeSubstage condenser tnfcusable,3-lens, swing-out top mount, irisdiaphragrni

.Polanoid polanizer: rotatable 36VPolaroid analyzer: in sliding mountBentrand lens: rentenableStace: 115mm diameter, revolves360 reads to h' with vernier-2Conpensators quarter-waneplate and finst order red plateFocusing: both coarse and hone

FREE TEN-DAY TRIAL

Quantity prices on three or moreAccessnry mechanical stage $14.75

-'iI Please rush UNITRON's Microscope Catalog 4D-1 I

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1688X'

Nxewv ProcductsThte inforomation reported here is obtcaieted from

manflatcactuarers an?d frontt othler sources consilereelto he reliable. Neithler Science nior the wvriter tvs-sumes responsibility for the accuracY of thc in-formolations. All issc/iirices. conzcernisIsn itemits listedshoulcl be caddressecd to the mncufacturer. In-cluce the dlcpacrtmotent niustber in your inquirv

* ATMOSPHERIC PARTICLE MONITORpresents on a strip-chart recorder arecord of aerosols present in the rangefroml 0.03 1 to anx desired tipper limiit.Counting rate is 1000 particles per-minute with a I -percent coincidenceloss at a standard floxx rate of 0)0cnmn5ain. The record is divided into Ssubranges that are recorded in sequeniceat intervals that can be predeterminedin length. The unit is continually self-calibrated. An alarill system can be setto operate if concentration in any ofthe subranges exceeds a predetermi inedValuLe. (Rovco Instrumnents, Inc.. Dept.Sci569. 365 San Antonio Rd.. NIoLun-tain Viex, Calif.)

* CURRENT-SURGE GEN"ERATOR fLuriishessingle half-xxwave sinusoidal suree cuLr-rents adjjustable hetxxeen 5 andi 75 amlpat a nmaxiimuma repetition rate ol' fourper mintite. Provision is made to mon-itor the output xxith an oscilloscopethrough a 50-mv shunt. A synchroniza-tion signal is provided. (Wallson Asso-ciates. Dept. Sci570, 9 1 2 WestfieldlAve., Elizabeth. N.J.)

* TEM PERATLURE StENSOR is designed forin-xwall locaLtions in steel struLctuLreshavin(y a section thickness 1,4 in. orgreater. Chromel-AluMel Is the juLnc-tion material ofTered as standard. B3odvlengths are ax ailable in in. incre-ments frotl 1' 4 to 3 '2 in. Therimio-couplc jLinction location is detertllincdito +t).t)t)2 in. or less in standl,Lard incre-ments of Il s in. from1 0.t)01 in. (froimiheated suLrface) to 0.005 in. (from1 uLt-heatedl surface). (American Standard,Dept. Sci57 1. 369 \Vhhi`sn1.rn RdI.,Mountalin Viexx . Calif.)

* RiFSOLVER TEST STAN[) is a shaft-ro-tation-positioning dxe ice consistint, ofan optical coincidence rea.iding, svstemsaid to have +2 -sec accuracx. a rackand gear for positioning. and ain adapterplate aind coupling. Angulalr positioI isread directly to the nicarest second ofarc. (\V. and L. E. Gurley. Dept. Sci-573 lTroy, N.Y.)

* CAxTHODE RAY Ttl BE is designed forlow deflection voltage, less thatn 15v/ in., to permit design of comiipa.ctequipmaent and trCansistor circuitr.Light oLitpUt is said to be high in relal-tion to the accelerating volta(ge used(5O)( volts). Post acceleration is usedto illiniiize distortion. (Allen B. Du-Nlont Laboratories, Inc., Dept. Sci574,Clifton, N.J.)

* REFERFNCE-VOI TAGE SOURC E providesa-c voltage output from 1 to 50(1 voltsr.m.s. adjustable in 0.1-volt steps andby multiturn potentionmet.er within steps.Output is 5 anmp or 25 watts, which-ever is less. Frequencies selectable are60, 400, and 10O) cv/sec. Accuracy issaid to be +0.1 percent or +5 mv.frequency stability 1.0 percent, andharmonic distortion less than 0.3 per-cent. Output impedance xith a constantresistive load is approximnately 0.01ohnm. (Cohu Electronics Inc., Dept.Sci572, 5725 Kearnv Villa Rd., SanDiego 12, Calif.)

* PHOTOMETER measures the differencein intensity of two light sources ornmeasures and records each intensitvindependently. Sensitivity of each scaleis adjustable over a ten to one range.AcCUcracy is salid to be -0.5 percent ineach channel aind stability +0.1 per-cent per channel per day. Five rangesfrom 0.001 to 10 /,,a full scale are pro-x ided. Commerciallv avlailable photo-tuLbes or multiplier phototubes may beuised. (Eldorado Electronics, Dept.Sci575, 2821 Tenth St., Berkeley 10,Calif.)

N OSCILLOSCOPE CAMERA, for 5-in.oscilloscope, is of modular design foradaptability to a xxvide range of object-to-inmage ratios. Accessories inClude abinocular viexing hood; adaptor to re-cord up to ten traces on a single 1'ramiie;35-tilil pulse camiera: 35-nmm contin-uOuIs motion camera; data chaminberN ith wvatch, platen. and counter; datacard; exterrial focusing control; andelectric shutter actuator. (Beattie-Cole-man Inc.. Dept. Sci566, 1090 N. OliveSt.. Anaheinm Calif.)

* DISPLACFI1MiNTr TRANSDUCERS of dif-ferential-transformer types are said tohave nonlinearity of 0.3 to 0).4 percentover 34 of full-range length. Six modelsr.ange itl length t'romi II' to 1 7 in. withdiamleter 0.5 in. Operating temlperaturerange is -100( to +350'F. Operatingfrequency is 400 cv sec. Repeatabilityis said to be +0.0)1 percent. (PacificElectroKinetics, Dept. Sci577, 329 S.Vermont Axe.. GlenduLra. Calif.)

* TIMER uses a filtered poxxer supplyPfeeding an RC netxxork throuLgh a tran-sistor to operate a relax at the end ofthe timing c c1. No wx arMLup time isrequired. The instrutilent is rated at3 x it)' operatioins. xvith accuracy saidto be + 1 percent. Contacts are rated15 anmp at 115 volts a-c. Direct-currentmodels are availlble. FLlll scale rangesare available fronm to 12t) sec. (Auto-matic Timing and Controls Inc., Dept.Sci581, King of Prussial. Pa.)

JOSHUA STERNNctiott(l BurJeaut of Staltarl,s.Washtittgton, D.C.

SC-IENCE, VOL. 131