1030CTECHNICAL NOTES

Book Review Technical Notes

Diffraction Gratings as Measuring Scales.

JOHN GuLD. Oxford University Press, London, 1960.Pp. 211+vii. Price $5.60.

The various applications of Moire fringes to metrology andprecision machine control are discussed in this book, which servesas the instrument designer's supplement to Guild's discussion ofthe theory and principles of Moir fringes: Te InterferenceSystems of Crossed Diffraction Gratings: Theory of Moir Fringes,Monographs on the Physics and Chemistry of Materials,Clarendon Press, Oxford, 1956. Although the present volumegives a brief summary of the theory, any serious student of thesubject is referred first to the earlier volume, which presents amore complete treatment of the principles involved.

Moir fringes, briefly, are the fringes observed normal to therulings when two identical transmission gratings are super-imposed, the gratings being oriented with a very slight anglebetween their respective rulings. These fringes correspond to theloci of the intersections between the two sets of rulings. As onegrating is moved relative to the other in a direction normal totheir rulings, the fringe pattern moves one fringe for each gratingdisplacement of one ruling. Devices utilizing Moir6 fringestherefore measure linear displacements in terms of grating rulingintervals. In the case of radial gratings, the same principle isapplied to angular measurement.

The present volume is a compendium of the very extensiveexperience of the National Physical Laboratories in this field.The descriptions are very detailed and the presentation is aimedat a wide audience with limited experience in optics and elec-tronics. The treatment may therefore appear somewhat too ele-mentary and pedantic to readers of the J. Opt. Soc. Am. Mr. Guildgives a very straightforward accounting of the advantages andthe limitations of various applications of Moir6 fringes in metrol-ogy and industry, and the prospective user is given a sufficientlydetailed and objective account to judge in the individual casewhether the application of Moir6 fringes techniques will net thedesired results.

The timing of a book of this nature, one which is concernedwith techniques in a new and rapidly developing field, is alwaysdifficult. In the present instance, the preparation of the manu-script was somewhat premature, but the book is fortunatelybrought up to date by a 28-page appendix on recent developments.This section suffers somewhat from over-condensation and alludesonly briefly to the possible existence of digitalized fringed inter-polation. Circuits for such interpolations have been developedelsewhere for interferometric fringe counting, and their applicationto Moire fringes is an obvious extension.* The digitalized output of a Moire fringe apparatus is wellsuited for input to digital computers via punch card or tape,and some mention of such application would have been in order.Industrially, the most obvious application is to the digitalizedprogramming of machine tools for intricate manufacturingoperations by means of Moir6 fringe servocontrols, and somemention of these should also have been made.

Despite such minor drawbacks relative to the more sophisticatedapplications, the basic features and characteristics of Moir6fringe techniques are well presented. These techniques do not asyet approach the accuracy and precision possible with inter-ferometric fringes, but fall within the range of precision achievedby the very best screw comparator. There will doubtless bemany applications of Moir6 fringe techniques in both laboratoryand industry in the near future and this book is required readingfor anyone contemplating such applications.

K. G. KESSLERNational Bureau of Standards

Collection of Papers on MicrowaveOptics, Diffraction, and Scattering

Published by OTS

A two-volume bibliography of 61 papers by authorities onvarious aspects of microwave optics, diffraction, and scatteringhas been prepared for the Air Force and released to science andindustry through the Office of Technical Services, Business andDefense Services Administration, U. S. Department of Commerce.

Volume 1 discusses microwave optics. Abstracts of papersare grouped by subject under the following categories: lenses andreflectors, caustics and aberrations, Fourier transforms andcommunication theory, microwave optics of artificial dielectricmedia, and microwave interferometry and the Faraday effect.

The second volume discusses diffraction and scattering.Abstract topics include: electromagnetic theory, general tech-niques, geometric optics limit in diffraction theory, asymptoticdevelopments, diffraction by apertures, scattering by specificbodies, and radiation patterns of antennas.

Both volumes contain an introduction and an author index,and Volume 1 contains a reference list of supplementary publica-tions. The bibliography, Tire McGill Symposiun on MicrowaveOptics, B. S. Karasik and F. J. Zucker, Air Force CambridgeResearch Center, April 1959, may be ordered from OTS, U. S.Department of Commerce, Washington 25, D. C. The twovolumes are: PB 161450 Microwave Optics (Part 1), 142 pages,$2.75; PB 161451 Diffraction and Scattering (Part 2), 250 pages,$3.50.

Announcement of New NBS Publications

Vibration-Rotation Structure in Absorption Bands for theCalibration of Spectrometers from 2 to 16 Microns, by Earle K.Plyler, Alfred Danti, L. R. Blaine, and E. D. Tidwell, Natl. Bur.Standards (U. S.) Monograph 16, issued June 21, 1960, 20 pages,20 cents. (Order from the Superintendent of Documents, U. S.Government Printing Office, Washington 25, D. C.)

With the influx in recent years of finer prism and small-gratingspectrometers, a need has arisen for more thorough and precisecalibration in the infrared region. This monograph helps fill theneed by remeasuring and tabulating the absorption bands ofcommon gases to obtain an accuracy of about 0.03 cm-' through-out the 2- to 16 -a range, and to provide good calibration pointsat frequent intervals. Only available or easily obtainable sub-stances have been used in this work, so that laboratories shouldexperience little difficulty in applying this method. The calibrationmaterials include H20, C02, CO, HCI, HBr, NH3 , C2H2, CH 4,N20, and a polystyrene film.

Approximately 600 rotation-vibration lines are illustrated in20 spectrograms. Wave numbers are listed in companion tableswith considerable intercomparison with data obtained in otherlaboratories. Characteristic features of the individual bands arealso discussed briefly.

Table of Wavenuroibers, 'olumie 1-2000 A to 7000 A, andVolume II-7000 A to 1000,u, by C. D. Coleman, W. R. Bozman,and W. F. Meggers, Nati. Bur. Standards (U. S.) Monograph 3,

Volume I, issued May 2, 1960, 500 pages, Volume 1I, issuedMay 16, 1960, 534 pages, S6.00 each. (Order from the Superin-tendent of Documents, U. S. Government Printing Office,Washington 25, D. C.)

Analysis of the light emitted by excited atoms is a widely

used method for obtaining information on atomic-energy levels

and electron configurations for individual atoms and ions. These

Vol. 501030

PERSONAL IA

data are in constant demand by physicists, chemists, spectrog-raphers, and astronomers.

This monograph presents a new and greatly expanded two-volume table for converting wavelengths in standard air towave numbers in vacuum, by using the index of refraction of airit computed from Edlen's 1953 equation. Recent improvementsin infrared detectors and infrared spectrographs have greatlyextended the range over which accurate measurements of longerwaves can be made. Since Edlen's formula fits the data withinthe experimental accuracy, the tables include the range from1u(10 000 A) to 1000,u. This area is particularly important inthe fields of astrophysics and molecular spectroscopy.

Wave numbers are shown to the nearest 0.001 cm-', andproportional tables are given for linear interpolations betweenentries of X. The wavelength differences, vacuum-air, X(n-1),and the refractivity of standard air in the form (n-1) X 1000 arealso included.

New Description of Tlorium Spectra, by Romuald Zalubas,Natl. Bur. Standards (U. S.) Monograph 17, issued June 21, 1960,103 pages, 65 cents. (Order from the Superintendent ofDocuments, U. S. Government Printing Office, Washington25, D. C.)

This monograph presents the wavelengths and estimatedintensities in electrodeless lamp and spark sources for 15 121lines of Th I, Th II, Th III, and Th IV in the spectral rangefrom 2000 to 11 550 A.

Since this table contains more than twice as many lines ashave heretofore been published, it should meet all of the presentrequirements for spectrochemistry and for an extension of thestructural analysis of Th I and Th II between the wavelengthlimits of 2000 and 12 000 A. At least three sets of plates in everyregion have been secured and measured by "hand and eye."Most of the lines have been measured on three plates and someof them on as many as eight plates.

Previously published standard thorium wavelengths arerounded off to three decimal places and are specifically indicatedin the table. This is done to make the list more convenient forusers of thorium standards.

Bibliography on Molecular and Crystal Structure Models, byDeane K. Smith, Natl. Bur. Standards (U. S.) Monograph 14,issued May 20, 1960, 7 pages, 15 cents. (Order from Superin-tendent of Documents, U. S. Government Printing Office,Washington 25, D. C.)

This monograph presents a bibliography on molecular andcrystal-structure models used extensively in research and asteaching aids.

The references are classified into those discussing models ingeneral, static models, dynamic models, or construction devices.The static models are further classified as molecular (Fisher-Hirschfelder-Taylor type), closed packing, open-molecular, open-crystal structure, open with parallel rods, polyhedral, andmiscellaneous models. A short annotation is given which describesthe model types and indicates the more significant articlespertaining to them.

Personalia

Herbert Friedman and Richard TouseyElected to

National Academy of Sciences

Two members of the Optical Society of America have beenhonored by election to the National Academy of Sciences:

HERBERT FRIEDMAN

Herbert Friedman, Superintendent of the Atmosphere and Astro-physics Division, U. S. Naval Research Laboratory and RichardTousey of the Rocket Spectroscopy Branch of the Atmosphereand Astrophysics Division, U. S. Naval Research Laboratory.

Dr. Herbert Friedman received his B.A. from Brooklyn College(1936) and Ph.D. from Johns Hopkins University (1940).After a year as an instructor in physics at J.H.U., he joined thestaff of the Metallurgy Division of the U. S. Naval ResearchLaboratory. In 1942 he became Head of the Electron OpticsBranch and in 1958 was appointed Superintendent of theAtmosphere and Astrophysics Division at N.R.L. Since 1949 hehas been engaged in upper-air research with rockets, particularlyin the field of solar-terrestrial relationships. He serves as amember of the Committee on Optical and Radio Astronomy ofthe Space Science Board. Dr. Friedman received the NavyDistinguished Civilian Service Award in 1946 and the AnnualAward of the Society for Applied Spectroscopy in 1957. In May,1959, he received the Department of Defense DistinguishedCivilian Service Award. His professional affiliations are asfollows: Member, National Academy of Sciences; Fellow,American Physical Society; Fellow, American Rocket Society,Chairman, Physics of Atmosphere and Space Committee of theAmerican Rocket Society; Member, National Board of Directors,American Rocket Society; Member, Advisory Committee of theNational Radio Astronomy Observatory; Member, Committeeon Cosmic Terrestrial Relations, American Geophysical Union;Member, Washington Academy of Sciences; Fellow, AmericanAcademy of Arts and Sciences.

After receiving his bachelor's degree from Tufts University in1928, Richard Tousey undertook graduate work in the Depart-ment of Physics at Harvard University. He received his Ph.D.degree in 1933 under Professor Theodore Lyman for the deter-mination of the optical constants of fluorite in the vacuumultraviolet. The two following years were spent at HarvardUniversity as an instructor in physics and as Bayard-CuttingResearch Fellow. From 1935 to 1941 he was a research instructorin physics at Tufts University. In 1941 he joined the staff of theOptics Division of the U. S. Naval Research Laboratory, wherehe began a program of upper-atmosphere research. His firstwork was on brightness of the sky and the visibility of stars,and was the result of measurements conducted from high-flyingaircraft. Since the inception of rocket research in 1946, he hasbeen in charge of a program of spectroscopic work from rockets,concentrating in the study of the solar spectrum in the extremeultraviolet. Results of this program include the first extensionof the solar spectrum into the ultraviolet, high-resolution solarultraviolet spectra, the discovery of many emission lines in theultraviolet spectrum of the sun, the determination of the profileof the Lyman alpha line of hydrogen, the measurement of thevertical distribution of ozone, and the direct measurement of the

1031October 1960

NECROLOGY V 5

altitude of several night airglow emissions. He guided the NavalResearch Laboratory program of research on the visibility ofearth satellites and was a member of the Science ProgramCommittee of Project Vanguard. At present he is head of theRocket Spectroscopy Branch of the Atmosphere and AstrophysicsDivision.

H. F. STiruSON

RICHARD TOUSEY

In 1945 Dr. Tousey received the Meritorious Civilian ServiceAward for the design and development of a reflector gun sight,and in 1958 the E. 0. Hulburt Award for accomplishment in avariety of subjects in physical and physiological optics and...pioneering and continuing investigations of the spectrum of thesun and the upper atmosphere by means of rocket-borne instru-ments. In October, 1959, Dr. Tousey and three colleagues wereawarded the Photographic Society of America's Progress Medalfor 1959, based on the first Lyman alpha pictures of the sun,obtained from a rocket flown on March 13, 1959, at White SandsMissile Testing Grounds. He is the author and co-author ofmany papers in numerous scientific journals.

Dr. Tousey is a Fellow of the American Physical Society andthe Washington Academy of Sciences. He is a member of theAmerican Geophysical Union, the American AstronomicalSociety, the Washington Philosophical Society, the InternationalAstronomical Union, the International Union of Scientific Radio,the International Union for Geodesy and Geophysics, the ArmedForces-National Research Council Committee on Vision, andthe Rocket and Satellite Research Panel.

Dr. James H. Schulman

James H. Schulman, Head of the Dielectric Branch, SolidState Division, of the U. S. Naval Research Laboratory, hasaccepted a position with the London Branch of the Office ofNaval Research. Dr. Schulman, a frequent contributor to theJournal, has been a member of the Optical Society since 1952.

Dr. Stimson has pioneered many scientific advances in thefield of heat measurement and is recognized as one of the foremostauthorities in the world on the International Temperature Scale.

His activities have included important research on the accuratedetermination of the thermal properties of water and steam, aspart of an international program for the production of steamtables to be used as a basis for engineering and power plantdesign. As a member of the Advisory Committee on Thermometry,he played a major role in drafting the International TemperatureScale of 1948 and has recently completed work on a text revisionwhich may be adopted at the 1960 meeting of the GeneralConference on Weights and Measures.

In 1949, Dr. Stimson received from the Secretary of Commercethe Silver Medal Meritorious Service Award "for long outstandingscientific accomplishment in the measurement of temperaturesand thermal properties."

For the past several years, he has been working on a programof gas thermometry to determine the differences between theInternational Temperature Scale and the Kelvin ThermodynamicScale.

Born in Leicester, Massachusetts, in 1890, Dr. Stimson attendedClark University, where he received his A.B. in 1910, his M.A.in 1911, and his Ph.D. in 1915, majoring in physics andmathematics. In 1916, he joined the Bureau of Standards as alaboratory assistant.

Dr. Stimson is a member of the American Physical Society,the American Association for the Advancement of Science, theWashington Academy of Sciences, and a past president of thePhilosophical Society of Washington. He has been a member ofthe Optical Society of America since 1922.

NecrologyDr. Stimson Retired from National

Bureau of StandardsDr. H. F. Stimson, a senior physicist in the Temperature

Physics Section of the Heat Division, retired on April 30 aftermore than 42 years with the National Bureau of Standards.

L. E. PitzerMr. L. E. Pitzer, who was with the U. S. Steel Company in

Pittsburgh, Pennsylvania, and a member of the Optical Societyof America since 1946, passed away recently.

1032 Vol. 50

TECHN I CAL CALEN DAR 1033

27-29 National Paint, Varnish and Lacquer Association,Chicago, Illinois

31-2 Society of Rheology, Mellon Institute, Pittsburgh,Pennsylvania

October

3-5 7th Annual Ottawa Symposium on Applied Spectro-scopy, Ottawa, Canada

4 New York Section of Society for Applied Spectroscopy,Esso Research Center, Linden, New Jersey

4-22 International Committee of Weights and Measures,Sevres and Paris, France

6-9 American Association of Textile Chemists and Colorists,Philadelphia, Pennsylvania

12-14 American Ceramic Society, Bedford, Pennsylvania12-14 Optical Society of America, Somerset Hotel, Boston,

Massachusetts14-15 Society of Photographic Scientists and Engineers,

Washington, D. C.20-22 Acoustical Society of America, Sheraton Palace Hotel,

San Francisco, California

November2-4 Eastern Analytical Symposium, Hotel New Yorker,

New York, New York9-11 Pittsburgh Diffraction Conference, Mellon Institute,

Pittsburgh, Pennsylvania25-26 American Physical Society, University of Chicago,

Chicago, Illinois: Thirteenth Annual Conference onElec-Techniques in Medicine and Biology, sponsoredby Instrument Society of America, with IRE andAIEE cooperating, Washington, D. C.

DecemberAmerican Physical Society, Berkeley, California

October 1960

Technical Calendar