SCIENCENEW SERIES9 FRIDAY, FEBRUARY 18, 1944 SINGLECoPIEs, .15

Bausch & Lomb Contour Measuring Projector

Thmakeprod

Today Precision Must Be CommonplaceAmerican fighting men on our screen, the B&L Contour Projector permits exactfighting fronts depend upon measurements or comparison with an enlarged tem-production line accuracy... for plate drawing at magnifications great enough for

ten-thousandths of an inch vari- easy and accurate dimensioning.ationon theproduction line can Here again is a Bausch & Lomb peacetime develop-mean the difference between a ment that serves America at War. The B&L Contourhit or a miss on the battleline. Measuring Projector is helping speed production of

Le Bausch & Lomb Contour Measuring Projector fighting tools for our fighting men.es such accuracy possible on the fastest moving For Bausch & Lomb Instruments essential toSuction lines, because it takes many vital inspec- Victory-priorities govern delivery schedules.

tion jobs "off the surface plate- and eliminates thetedious, time-consuming computations of the "sinebar." Inspections for accuracy become routine jobs.Throwing an accurate, sharply defined shadow im-

age of the object under examination on a translucent

BAUSCH & LOMBOPTICAL CO. . ROCHESTER, NEW YORK

ESTABLISHED 1853

AN AMERICAN SCIENTIFIC INSTITUTION PRODUCING OPTICAL. CLASS AND) INSTRUMENTSFOR MILITARY USE, EDUCATION, RESEARCH, INDUSTRY AND EYESIGHI'' (,(RRECTO1'10N

Science: published weekly by The Science Press, Lancaster, Pa.E'nt~tered as secondl -clasgs matter July iS, 1923, at the Post Office at Lancaster, Pa., under the Act of March 3, 1879.

2 SCIENCE-ADVERTISEMENTS

r

Bacto-Agar- Bacto-Agar is a purified Agar prepared fromdomestic material. In the manufacture ofBacto-Agar extraneous matter, pigmented portions,and salts are reduced to a minimum, so that thefinished product in the form of fine granules willdissolve rapidly, giving clear solutions.

Bacto-Agar is distributed only for use inbacteriological culture media upon propercertification by the purchaser.

Bacto-AsparagineBacto-Asparagine is a purified amino acid

widely used in synthetic culture media and in thepreparation of tuberculin.

Specify 'tDIFCO"THE TRADE NAME OF THE PIONEERS

In the Research and Development of Bacto-Peptone andDehydrated Culture Media.

DIFCO LABORATORIESINCORPORATEDDETROIT, MICHIGAN

LaMottePhosphate Comparator

The phosphate treatment of boiler feed water to prevent cor-rosion has given rise to the need of a rapid, simple and ac-curate method of analysis, so that the proper control mightbe applied. This new LaMotte comparator employs tworeagents, only one of which is in solution form. The rangeof concentration covers 0 to 100 ppm of phosphate. Higherreadings made by dilution principle. Unit includes necessary pipettes, tubes, reagents in comparator with full instruc-tions. Price $15.00 F.O.B. Towson 4, Baltimore, Md.

LaMotte ChemicalProducts Co.

Dept.Towson 4, Baltimore, Md.

I

NUTRITION OF THE DOGBy Clive M. McCay

Professor of Nutrition, Cornell University

An understandable summary of the in-formation necessary for a proper and eco-nomical feeding of dogs. ". . . a scientificstudy. on this subject that can be used bythe layman."

140 pp., Ill., $1.50Order from your bookstore or from

Comstock Publishing Co., Inc.124 Roberts Place, Ithaca, N. Y.

MATHEMATICS DICTIONARYby Dr. Glenn James and B. C. James.

Recalls arithmetic and subsequent mathematics.Saves time and worry at nominal cost. Send $3.00to Digest Press, Dept. 4B, Van Nuys, Caifwornia.

FOR SALE BIOLOGICAL PUBLICATIONSFifty years accumulation of leaflets to books in all branchesof Biology. Reports, proceedings, etc.: U. S. Biological Sur.vey, Smithsonian, National and other museums, states, socie-ties, etc. Exploration, travel and big game hunting in manylands. State in what branch interested and send for pricelist. J. Alden Loring, Owego, New York.

Klett made ...Glass Absorption Cells

Fused under high temperature with acid, alkali and othersolvent resisting cement. Optical flat walls. Many stock sizes.

Special requirements made to order.Sole manufaturer In the VnitedStat of fused Eleetrophoresis colls

Makers of complete Electrophoresis Apparatus

Klett Manufacturing Co.179 East 87th Street, New York, New York

I

SCIENCE-ADVERTISEMENTS, VOL. 99, No. 25642

ALWA41.4ma~

* Choline Chloride, Cystine and Methio.nine, prepared in the Research Laboratoriesof S. M. A. Corporation, are available tothe laboratory investigator in these conve.nient amounts.

CHOLINE CHLORIDE25 gram bottle........... . $1.75100 gram bottle .4.65

1000 gram bottle. 35.00

1-CYSTINE10 gram bottle .$1.00

100 gram bottle .7.501 pound bottle.15.50

di-METHIONINE1 gram bottle . . $1.00

10 gram bottle. 9.00100 gram bottle .60.00

For quotations on larger quantities, writeResearch Laboratories, S. M. A. Corpora.tion, Chagrin Falls, Ohio.

S. M. A. CORPORATION

DIVISION NINCORPORATED

VOL. 99, No. 25644 SCIENCE-ADVERTISEMENTS

When the lights go on again in GrigoriopolThree short years ago Grigoriopol was a thriving cityof the Russian Ukraine. Today it is a scene of desola-tion ... victim of ravaging Hitlerite hordes.But some day-soon we hope-lights will go on

again in Grigoriopol, and in other Allied cities nowunder the Nazi heel.When that time comes ... thanks to a new idea in

modern warfare . . . emergency electric power will beavailable to revitalize industries in war torn cities-immediately after they are retaken from the enemy.

This new idea-a self-contained POWER-TRAIN-hasnow been made a reality by the engineering brains andskill of Westinghouse.Ten of these POWER-TRAINS are now being built by

Westinghouse for use by the United Nations ... eacha complete 5000 kw power house on wheels, big enoughto serve a community of 15,000.Each- POWER-TRAIN consists of 8 cars. Ingeniously

assembled in these cars are: a 5000 kw steam turbo-

generator, boilers, power stokers, boiler feed pumps,air-cooled condensers, auxiliary Diesel engine, livingquarters for the crew-even conveyer equipment forhandling coal which will be mined locally for fuel.

Because cooling water is not always available, air-cooled condensers are used to recover, as water, a highpercentage of the exhaust steam from the turbine.From switchgear to turbo-generator, each POWER-

TRAIN is a complete 5000 kw mobile power house, readyto go to work at a few hours' notice ... in sub-zerocold or tropical heat of the desert.And remember-the same Westinghouse engineer-

ing brains and skill that developed the POWER-TRAINwill be available, after Victory, to create and buildbetter products for you.Westinghouse Electric & Manufacturing Company,

Pittsburgh, Pennsylvania.Tune in John Charles Thomas,NBC, Sundays, 2:30 p.m., E.W.T.

WestinghousePlauls in 25 cAm sm yEvrywher

SCIENCE-ADVERTISEMENTS4

SCIENCE-ADVERTISEMENTS

THE RIGHT COMBINATION

ho 5, IT'S

LAND,

SEA, AND

AIR POWER

IT'S

HIGHEST QUALITY

COMPLETENESS OF LINE

ESPECIALLY DESIGNED CONTAINERS

NATION-WIDE DISTRIBUTION

RELIABLE SERVICE

Always Specify MERCK LABORATORY CHEMICALSYou will get THE RIGHT COMBINATION.

MERCK & CO., Inc. ante A ea RANWAY, N. i.New York, N. Y., Philadelphia, Pa., St. Louis, Mo., Elkton, Va., Chicago, Ill., Los Angeles. Cot.

In Canada: MERCK & CO., Ltd., Montreal and Toronto

FEBRwAuy. 18, 1944

SCIENCE-ADVERTISEMENTS

for accurate linear measurements of short rangeGAERTNER

MICROMETER SLIDESfitted with microscope or telescope, permit- horizontal. ". i i1. X - ~~~~~~~~~~~measurements

depth measurements

Vertical micrometermeasurements focusing

A most desirable feature of these instruments is the diversity of applications possible. In addition to the usesindicated, displacements on small objects can be measured by mounting them directly on the slide. Two slidescan be mounted to form a small coordinate comparator. Etc., etc.

RANGES: up to 4 inches (100 mm) * READINGS: to .00005 inch (0.001 m) by vernier

THE GAERTNER SCIENTIFIC CORPORATION1204 Wrightwood Avenue Chicago 14, U. S. A.

AUTOTECHNICON

U. S. Patent No. 21,157,875and Other Patents Pending.

THE TECHNICON CO.NEW YORK, N. Y.

VOL. 99, No. 2564

SCIENCE-ADVERTISEMENTS

ADAMS SAFETY-HEAD CENTRIFUGEImproved Model As Supplied to U. S. Army

5000* R.P.M. on D.C.This centrifuge offers important advantages over the conventional units. The tubes are sus-pended at a fixed 520 angle-thus faster sedimentation is achieved by the shorter distanceparticles are required to travel . . creating mass, and reaching the bottom more quickly.The tubes remain in the angular position and no stirring up of sediment results.

CT-1001 ADAMS SENIOR SAFETY-HEAD CENTRIFUGE for SIX 15ml. TUBES.Exclusive of tubes or shields. . over....... nventional...it. Each $49.50CT-100O Same as above,but complete with six round bottom brass shields withrubber cushions and three each graduated and ungraduated taper bottom 15 ml.glass tubes.'Without protective cap or underguard .no........g.....f .....Each $52.50CT-1055 UNDERGUARD..SENIO Each $ 3.50

CT-1050PROTECTIVE CAP.............................. Each $ 2.50Above centrifuges have universal motors for 110-volt A.C. or D.C. current. Ad-ditional charge of $2.00 is made for 220 volt universal motors.

* With underguard No. CT-1055 with six 15 ml. tubes loaded.4200 R.P.M. on A.C. with same load.

MICRO and SEMI-MICRO tubes (5 ml. to 0.5 ml.) can be accommodated by purchasing extrashields. No adapters are required.JUST ISSUED . . . New literature Form 309R2 ADAMS CENTRIFUGES listing allmodels . . . Write for a copy.

CLAY-ADAMS ICC.ADAMS

FEBRUARY 18, 1944 7

8 SCEC-DERIEET Vo.9,N.26

9mf'~e 5ewith the

SMALIWOOD BIOLOGICAL CHARTS

Interesting:::a .... _Chartslithographed in

Diagrammatic

Colors

Over 750Labeled Figuresand Diagrams

________________SIZE 24 x36 INCHESWith Tripod or WallBracket Mounting.

COMPLETE SET of 60 Charts, mounted on onechart head, on a single tripod, including 30 Bo-tanical and 30 Zoological Charts. $45.00

SEPARATE SET of either Botanical or ZoologicalCharts, 30 to a set, mounted in chart head, withportable tripod or wall bracket mounting. Each. 27.

WC.AM. WELCH SCIENTIFIC COMPANYEstablished 1880

1517Sedgwick Stree Chiag 10,he Illinois, U.S.A.oica

-1

bL

8. SCIENCE-ADVERTISEMENTS VOI.. 99, No. 2564

1517 Sedgwick Street Chicago 10, Illinois, U.S.A.

0OMS

SCIENCEVOL 99 FRIDAY, FEBRUARY 18, 1944 No. 2564

Galactic Evidences for the Time-Scale of the Uni- Special Articles:verse: DR. S. CHANDRASEKEHAR ..................................... 133 The Disintegration of Macromolecular Tissue Lipo-

Soviet Studies on Viruses: DR. W. M. STANLEY ............ 136 proteins: DR. ERWIN CHARGAFF and AARON BEN-DICH. The Optical Rotation of Cellulose and Glu-Obituary: cosides in Cuprammonium Hydroxide Solution:Recent Deaths ......... 138 RICHARD E. REEVES .......................... 147

Scientific Events: Scientific Apparatus and Laboratory Methods:The Polish Faculty of Medicine at Edinburgh Uni- A Still for the Continuous Production of Doubleversity; The Refrigeration Research Foundation; Distilled Water: DR. OLAF MICKELSON, W. W.The Institute of Aviation Psychology; The Lec- BENTON and JOHN A. PELAN..149tureship on Metallurgy at the University of SdoPaulo; Conference of the Institute of Food Tech- Scien ceNews.10nologists; The American Association for the Ad-

......................................... 138

Scientific Notes and News...........................141 SCIENCE: A Weekly Journal devoted to the Advance-ment of Science. Editorial communications should be sentDiscussion: to the editors of SCIENCE, Lancaster, Pa. Published everyThe Direction of Rotation in Spiral Nebulae: DR. Friday byV. M. SLIPHER. The Perfusion of Rat Livers: DR. THE SCIENCE PRESSCARL G. HELLER. Anthracite Coal Ashes for Root- Lancaster Pennsylvaniaing Cuttings: MILDRED P. MAULDIN. Joule Again:DR. JOSEPH 0. THOMPSON ....................... ................ 144 Annual Subscription, $6.00 Single Copies, 15 Cts.

SCIENCE is the official organ of the American Associa-Scientific Books: tioD for the Advancement of Science. Information regard-Biophysics: FRANK BRINK. Potash: DR. WILLIAM ing membership in the Association may be secured fromBiophsics:FRAN BRIN. Potsh: R. WILIAM the office of the permanent secretary in the SmithsonianHI. ROSS .. 146 Institution Building, Washington 25, D. C.

GALACTIC EVIDENCES FOR THE TIME-SCALEOF THE UNIVERSE'By Dr. S. CHANDRASEKHAR

YERKES OBSERVATORY, THE UNIVERSITY OF CHICAGO

AN important phase of modern astronomical re-search is concerned with the time scale of the universe,i.e., with the specification of a natural unit of timein which it would be most convenient to describe thechanging aspects of the astronomical universe. Statedin this manner, it is apparent that the solution to theproblem of the time scale will not permit us (not atany rate in the first instance) either to "date" thepresent epoch in a "fundamental" calendar or to fore-cast with definiteness the "end." What it would allowus, however, is to specify an interval of time in whichvarious aspects of the astronomical universe may beexpected to change appreciably. Conversely, the solu-tion to the problem of the time scale will ultimatelydepend on the study of a variety of different aspects'Address given before the Philosophical Society of

Washington on December 4, 1943.

of the universe and the establishment in each case of atime interval during which the aspect studied mightchange to an appreciable extent. And if such studiesshould lead us in most instances to time intervalswhich are of the same order of magnitude, it wouldnot be unreasonable to attribute to a unit of time ofthis order of magnitude a fundamental significance.It would appear that this is the only manner in whicha rational approach to the problem of the time scalecan be made. However, in formulating the problemin this manner it is evident that a certain element ofarbitrariness has been introduced into the discussion.But this is unavoidable and inherent in a problem inwhich the emphasis is on an order of magnitude andnot on an absolute measure.During the past twenty years many attempts have

been made to establish a time scale in the sense de-