case if the slides themselves were stacked and vieweddirectly. Thirty depth-frames per second are dis-played, each one consisting of ten slides shown se-quentially during a one-way excursion of the mirror;the display s blanked during the mirror flyback. The5 cm X 5 cn slides are mounted around the edge of one-half of a uniformly spinning disk and move through theprojector gate at 'about 40 m/sec. The flash lamppulses, of about 2 Msec each, are short enough to freezeeach slide image on the 20-cm square projection screen.The screen is translucent, and the rear of it is viewed inthe vibrating mirror. The mirror vibrations are syn-chronized with the spinning disk through special cir-cuitry using: photoelectrically derived position signalsfrom the disk.

The displays produced with this system so far havebeen an air-traffic control display similar to the com-puter-generatied one, although static, and a volumetricmatrix of colored alphanumeric symbols being evaluatedas a tool in depth perception testing of human subjects.

A study was also made of the feasibility of using abank of NIX IE tubes with the mirror, with variousnumerals being pulsed in appropriate sequences in orderto generate a spatial matrix of arbitrary numerals whichcould be altered at will in real time. The visual effectwas reasonably good, the single deficiency being thelow image brightness due to the fact that the tubesused were apparently not intended for the high-energyshort-duration pulses required in this use.

In a study of alternative methods of driving the mir-ror, for cases where large-screen on-the-wall displaysmight be used, we have assembled an electrostatically

driven mirror in which the Mylar forms one plate of acapacitor. The other plate is a rigid metallic sheetcoated with a silicone rubber compound to discouragearcing. The assembly is 38 cm in diameter, with a vari-able air gap a few millimeters in thickness. Experi-ments established that usefully large mirror deflectionscould be obtained with capacitor voltages in the 10-kVrange or higher. Electrical breakdown of the gap oc-curred sporadically and, although it was not done, couldprobably be eliminated through better insulation meth-ods.

In all of these displays, the depth effect is convincingand has readily been perceived as such by many un-trained observers. One restriction, of course, is thatthe mirror rim is a limiting aperture and must be fairlylarge if several observers are to view the display in closequarters. Another problem is the anomalous perspec-tive observed in the spatial image when the objectframes are alike in size. This effect is due to the in-creased magnification of the planar images at increas-ing distances from the mirror surface, although in manycases it can be preprogrammed out of the display byappropriate size-processing of the 2-D frame sequence.

The support of this work by The MITRE Indepen-dent Research Committee is gratefully acknowledged.Thanks are also due to A. Bark and to numerous othersfor their interest and encouragement.

References1. P. Vlahos, Inform. Display 2 (6), 10 (1965).2. J. C. Muirhead, Rev. Sci. Instr. 32, 210 (1961).

reported by STANLEY S. BALLARD, Department of Physics and Astronomy,University of Florida, Gainesville, Florida. Professor Ballard hopes to receive newsand comments for this column, which should be sent to him at the above address

Recent columns have been devoted to a discussion of scientificsocieties in general, with special emphasis on our favorite suchorganization, t~he Optical Society of America. This series hasterminated, but there are two or three clean-up items worth men-tioning. Most important of these is the fact that the Board ofDirectors increased the number of honorary members from five tosix, and then elected George R. Harrison in this highest class ofmembership. ])r. Harrison retired in 1964 after more than threedecades at the Massachusetts Institute of Technology, where heserved first as professor of physics and director of the researchlaboratories acl then as dean of science. He is well-known tothe older members of OSA since he served as editor of its journalfor the ten-year period 1940-50, and as president of the Societyfor the two-year period 1945-46. George Harrison's cheerfulpresence was a valued feature of OSA meetings for many years;his vigorous presentations of technical papers and his friendlyand contagious wit were always appreciated. His election as anhonorary member of the Society seems highly appropriate.

As noted in my January column Appl. Opt. 6, 50 (1967)],there is a vacancy in the roster of honorary members that wascaused by the death of William F. Meggers, on 19 November 1966.The Committee on Fellows and Honorary Members will pre-sumably make a recommendation to the Board of Directors forfilling this vacancy and restoring the list of honorary members toits full strength of six.

Despite the invitation always stated at the head of this column,I receive relatively few comments about the items I discuss here,even though I attempt to make some of them sound at leastmildly controversial. One letter, recently received from a stal-wart OSA member, refers to my comments in the January 1967column on the poor attendance at the banquets ordinarily sched-uled. at meetings of scientific societies. He states: "Perhaps thesituation could be improved if a rule were passed prohibiting after-dinner speeches on science or technology. After a whole day oflistening to papers, many people want some relief in the evening.And in San Francisco [October 1966 OSA meeting-SSB], for

June 1967 / Vol. 6, No. 6 / APPLIED OPTICS 1087

instance, there were some well-known alternatives to the Societydinner, which attracted many members. Two banquets Ifondly remember are one of the Optical Society held in Rochester,where Crawford Greenewalt talked about hummingbirds, and anIRIS meeting at Fort Monmouth, where the after-dinner speakerwas a professional raconteur from Lisbon Falls, Maine." Futureprogram committees please take notice!

From time to time, during the several years I have been writ-ing this column, I have mentioned descriptive booklets andother valuable items that are available upon request from manu-facturers of optical equipment. Among these were the LaserTechnical Bulletins issued by Spectra-Physics, Inc., MountainView, California 94040. I note that there have been recentadditions to the list and that their Bulletin No. 5, entitled "Designof Optical Systems for Use with Laser Beams", is a ten-page, well-illustrated booklet written by D. J. Innes and A. L. Bloom anddated August 1966. Preceding issues in this series were BulletinNo. 4, "Noise in Lasers and Laser Detectors"; No. 3, "Some Dem-onstration Experiments in Optics using a Gas Laser"; No. 2,"Properties of Laser Resonators Giving Uniphase Wave Fronts";and No. 1, "Optical Properties of Lasers as Compared to Conven-tional Radiators". I am advised that copies of all these bulletinsare still available for those who request them. So also are reprintsof the article "Gas Lasers" by Arnold L. Bloom that appeared inAPPLIED OPTICS for October 1966 (Vol. 5, pp. 1500-1514),and a four-page technical memorandum "Retardation-Type,Laser Modulators" by James L. Hobart, dated January 1966.

Have you seen the attractive new quarterly journal OpticalSpectra? Volume 1, Issue 1, dated January 1967, reached mydesk on the first of March. This new publication appears to beassociated with the Optical Publishing Company, which haspublished the Optical Industry & Systems Directory for manyyears. Sample copies and information on this well-illustratednew publication can be obtained by writing to Optical Spectra, 7North Street, Pittsfield, Massachusetts 01201. The first issueis 86 pages in length and has a colorful cover showing hologramreconstruction with a nonlaser light source, utilizing color disper-sion to advantage. There are a dozen short articles or reportson various topics of interest to optical engineers and other per-sons working in the broad field of applied optics. As is usual withsuch advertiser-oriented publications, much information can alsobe gleaned from the advertising pages.

Reference has often been made to the unhappy fact that it isdifficult to find universities in which instruction is given in pure

and applied optics, other than the usual junior-level course inphysical (and sometimes geometrical) optics, and the conven-tional courses in atomic physics and spectroscopy. Afterthe Universities of Rochester and Arizona and a very smallnumber of others, a person interested in studying optics, par-ticularly on the graduate level, finds the picking very slim indeed.I have discussed this problem with the Research and EducationOfficer of the OSA, John A. Sanderson, and we agree that itwould be helpful to optics-minded students to publish a list ofschools where at least one professor is doing research in somefield of optics and where thesis or dissertation research could bepursued by graduate students. Any information that the readersof this column might submit would be most helpful in this com-mendable undertaking.

Meanwhile, still another College of Engineering is taking alead in giving graduate courses in engineering optics. This isPurdue University, and the program is under Warren H.Stevenson of the School of Mechanical Engineering. The em-phasis in the curriculum he is constructing is on principles funda-mental to the use of optical devices in research and commercialareas; it includes both theory courses and an extensive labora-tory. Thus, Purdue has joined the group of universities whereapplied and modern optics is taught in engineering colleges ratherthan in the physics departments-this group includes the Uni-versity of Michigan, University of Southern California, Massa-chusetts Institute of Technology, Northeastern University in Bos-ton, and others that may have been mentioned previously in thiscolumn. It would surely be appropriate to include a list of thisgroup of schools, along with an abbreviated description of theirofferings in pure and applied optics, in any compendium thatmight be drawn up to give a quick survey of optics instructionon the undergraduate and graduate levels in the U.S.A.

Further on this same theme, industrial organizations are theones that build the outstanding optics research centers, accordingto statements made by the president of Itek Corporation ofLexington, Massachusetts, when its new four million dollaroptical facility was shown to the public a few months ago.President Franklin A. Lindsay of Itek, according to a newspaperreport, stated that of the four or five outstanding optics researchcenters in the United States, all but one are company sponsored;the exception was the Institute of Optics at the University ofRochester. He traced this situation back to the 1930's, "whenmost university physics departments became enamored withelectronics, and little was done in optics."

Martin Rome has been named manager of the Photoelectric Divi-sion of Electro-Mechanical Research Inc., of Princeton.

1088 APPLIED OPTICS / Vol. 6, No. 6 / June 1967

June5-7 Royal Society of Canada Ann. Mtg., Ottawa Ex.

Sec., Royal Soc. Canada, Rm 1120, 100 Sussex Dr.,Ottawa, Ont.

5-9 Advanced ir Technology Course, Ann Arbor Engrg.Summer Courses, U. of Mich., W. Engrg. Bldg., AnnArbor, Mich. 48104

5-9 Atmospheric Physics Course, Ann Arbor Engrg.Summer Courses, U. of Mich., W. Engrg. Bldg.Ann Arbor, Mich. 48104

5-10 X-ray Spectroscopy Summer Clinic, Albany H.Chessin, Phys. Bldg. 214, SUNY, Albany, N.Y.12203

6-9 Conf. on Laser Eng. and Application, Washington,D.C. K. Tomi Yasu, GE Co., P.O. Box 8, 1 RiverRd, #37-465, Schenectady, N.Y. 12301

8-9 Molecular Absorption Spectroscopy Course, TorontoThe Chemical Inst. of Canada, 151 Slater St., Ot-tawa 4, Ont.

12-13 Intersociety Color Council, New York R. M. Evans,Eastman Kodak, Rochester, N.Y.

12-14 MINssbauer Spectroscopy Course, Wash., D.C. L.May, Chem. Dept., Catholic U. of Am., Wash,D.C. 20017.

12-14 Optical Thin Films and Multilayers Course, Roches-1:er Inst. of Optics, B & L Bldg., U. of Rochester,Rochester, N.Y. 14627

12-16 Molecular Electronic Spectroscopy Gordon Conf.,Nfew Hampton G. W. Parks., U. of R. I., King-

ston, R.I. 0288115-16 AAPT Mtg., Canton A. Romer, St. Lawrence U.,

Canton, N.Y.18-21 30th Ann. Mtg. Canadian Ophthalmological Soc.,

Ottawa Secretary, 1849 Yonge St., Suite 902,Toronto 7, Ont.

19-23 1t31h Internatl. Spectroscopy Colloq., Carleton U.,Ottawa C. S. Joyce, Pulp and Paper ResearchInst. of Canada, 570 St. John's Rd., Pointe Claire,Que.

20-24 Conf. of Oil and Colour Chemists' Assn., ScarboroughB. B. Hamblin, Wax Chandlers' Hall, Gresham St.,London, EC2, U.K.

20-28 Internatl. Comm. Illumination, on Plenary Mtg.,1.6th Quadrennial, Washington, D.C. L. Barbrow,U.S. Natl. Com. on Illumination, NBS, Wash.,D).C. 20234

21 IRDG Mtg, Oxford J. H. S. Green, NPL, Ted-dington, Mx, U.K.

21-23 APS Mtg., Toronto Ex. Sec., APS, Columbia U.,New York, N.Y. 10027

25-30 ASTM 70th Ann. Mtg. Statler-Hilton Hotel, BostonASTM, Race St., Philadelphia, Pa. 19103

26-28 AilL. Astron. Soc. Mtg., Williams Bay P. M. Routy,Princeton Observatory, Princeton, N.J.

27-July 2 2nd Internatl. ICO Colloq. on Thin Films, BudapestHungarian Soc. for Optics, Acoustics, and Tech-niques, Szabadsdgter 17, Budapest V, Hungary

28-30 Anm. Symp. Am. Glass Blowers Soc., Atlanta R. W.Poole, 100 Cedar Lane, Oak Ridge, Tenn. 37832

July

7-9 10th Bien. Congr., Canadian Assn. of Optometrists,Montreal C. Gareau, 2194 Sherbrooke East,Montreal, P. Q.

10-12 Astron. Optics Conf., London C. G. Wynne,Dept. Physics, Imperial College, Prince ConsortRd, London, SW7, U.K.

10-21 Fundamentals of Optics Course, Rochester Inst. ofOptics, B & L Bldg., U. of Rochester, Rochester,N.Y. 14627

17-28 Theory and Applications of Modern Optics Course,[UCLA R. E. Garrels, Phys. Sci. Ext., Rm. 62,Floelter Hall, UCLA, Los Angeles, Calif. 90024.

23-29 10th COSPAR Plenary Mtg., London COSPARSec., 55 Blvd. Malesherbes, Paris 8, France

24-Aug. 4 Introduction to Optical Data Processing Course,Ann Arbor Engrg. Summer Courses, W. Engrg.Bldg., U. of Mich., Ann Arbor, Mich.

31-Aug. 4 Color Measurement Seminar, Clemson School ofIndustrial Management and Textile Science, Clem-son U., Clemson, S.C. 29631

August7-11 17th Ann. Tech. Symp. SPIE, Los Angeles P.O.

Box 1716, Redondo Beach, Calif. 902777-18 Electromagnetic Measurements and Standards Course

NBS-Boulder Bureau of Continuation Educa-tion, Rm. 28, U. Memorial Center, U. of Colorado,Boulder, Colo.

7-18 Lasers: Theory, Technology and Applications Course,Ann Arbor Engrg. Summer Courses, W. Engrg.Bldg., U. of Mich., Ann Arbor, Mich.

14-18 6th Australian Spectroscopy Conf., Brisbane D.James, U. of Queensland, St. Lucia, Brisbane,Queensland, Australia

20-24 37th Ann. Mtg. Biological Photographic Assn.,Toronto S. N. Turiel, 33 N. Mich. Ave., Chicago,Ill. 60601

21-25 Recent Progress in Microscopy Mtg., Cambridge,U.K. MICRO-67, 41 E. 31 St., Chicago, Ill.60616

22-31 13th Gen. Assem. Internatl. Astron. Union, PragueAsst. Sec. Gen., c/o Astronomical Inst., CzechoslovakAcademy of Sciences, Budecska 6, Prague, Czecho-slovakia

27-Sept. 2 IUPAP 8th Conf. on Ionization Phenomena inGases, Vienna F. Viehbiick Oestereichische Stu-diengesellschaft fur Atomenergie, Lenaugasse 101082, Wien 8, Austria

27-Sept. 3 IUPAC Conf. and Congress, Prague R. Morf,IUPAC, o F. Hoffmann-La Roche and Co., 4002Basle, Switzerland

29-31 High Frequency Generation and Amplification Conf.,Cornell H. J. Carlin. Conf. Chee., EE School,Cornell U., Ithaca, N.Y. 14850

31-Sept. 2 APS Mtg., Seattle Ex. Sec., APS, Columbia U.,New York, N.Y. 10027

September5-8 Solid State Devices Symp., Manchester IPPS, 47

Belgrave Sq., London SW>, U.K.5--9 22nd Ann. Symp. Molecular Structure and Spectro-

scopy, Columbus K. N. Rao, Dept. Phys., OhioState U., 174 V. 18th Ave., Columbus, Ohio 43210

10--15 Illuminating Engineering Soc. Natl. Tech. Conf.Montreal IES, 345 E. 47th St., New York, N.Y.10017

10-15 9th European Congr. on Molecular Spectroscopy,Madrid J. Morcillo, Instituto de Chimia-Physica,Serrano 119, Madrid 6, Spain

10--16 Internatl. Conf. on Magnetism, Cambridge L. F.Bates, Dept. of Physics, 'The University, Nottingham,U.K.

11-13 Symp. on Atomic Spectroscopy, Gaithersburg K. G.Kessler, NBS, Washington, D.C. 20234

11--14 ISA Ann. Instrument-Automation Conf. and Exhibit,Chicago D. R. Stearn, ISA, Penn Sheraton Hotel,Pittsburgh 19, Pa.

11-15 Information Theory Symp., Delphi IEEE, 345 E.47th St., New York, N.Y. 10017

18-23 Internatl. Congr. on Photographic Science, TokyoOrg. Com. Sec., Tokyo College of Photography, 24Togocho, Nakano-ku, Tokyo, Japan

22 IRDG Mtg., Aberdeen J. H. S. Green, NPL, Ted-dington, Mx, U.K.

25-Oct. 7 Internatl. Assn. of Physical Oceanography, 15th Gen.Assem. and Symp., Berne Sec., Merentutkimuslai-tos, Inst. of Marine Research, Tahtitorninkatu 2,Helsinki 4, Finland

25-Oct. 7 Internatl. Assn. of Meteorology and AtmosphericPhysics, 14th Trienn. Gen. Assem. and Symp.,Lucerne Sec., co Meteorological Office, 815 BloorSt. W., Toronto 5, Ont.

29 IRDG, Bradford J. H. S. Green, NPL, Teddington,Mx, U.K.

late Conf. on Spectroscopy, Inst. of Petroleum, LondonMtgs. Sec., IEE, 61 New Cavendish St., London, W1,U.K.

October2-5 ASP-ACSM Conv., St. Louis Director, St. Louis

ASP-ACSM Conv., Box 2731, Soulard Stn., St.Louis, Mo. 63104

June 1967 / Vol. 6, No. 6 / APPLIED OPTICS 1089

2-5 17th Ann. Research Equipment Exhibit and Instru-ment Symp., Bethesda J. B. Davis, SMB, NIH,Bldg. 12A, Bethesda, Md. 20014

2-7 32nd Physicists Symp. of The German PhysicalSociety, Berlin E. Boersch, Physics Inst., Tech-nische Universitat Berlin, Hardenbergerstr. 34, Ber-lin 12, Germany

11-13 Optical Society of America, 52nd Ann. Mtg., Shera-ton-Cadillac, Detroit M. E. Warga, OSA, 115516th St., N.W., Wash., D.C. 20036

15-17 Symp. on Nonspecific Therapeutics in Ophthal-mology, Wroclaw E. Ogielska, Klinika Ocsna, Ul.Chalubinskiego 2a, Wroclaw, Poland

15-20 102nd Semiann. Conf. SMPTE, Chicago MichaelDenson, 9 E. 41st St., New York, N.Y. 10017

16-20 Soc. for Nondestructive Testing Mtg., ClevelandSoc. Off., 914 Chicago Ave., Evanston, Ill. 60202

25-31 2nd Internatl. Congr. on Reprography, CologneG. C. Grossel, German Soc. for Photography, Neu-markt 49, K6ln, Germany

26-28 SPSE Symp., on Unconventional Photographic Sys-tems, Marriott Motor Hotel, Wash., D.C. SPSEMain P.O. Box 1609, Wash., D.C.

29-Nov. 2 AFIPS, Fall Jt. Computer Conf., Los Angeles Exec.Sec., 211 E. 43rd St., New York, N.Y. 10017

November8-10 9th Eastern Analytical Symp., New York E. G.

Brame, Jr., Elastomer Chem. Dept., Du Pont Exp.Stn., Wilmington, Del. 19898

16-18 APS Mtg., New York City Ex. Sec., APS., Colum-bia U., New York, N.Y. 10027

AAS Mtg., Philadelphia G. C. McVittie, Dept.Astronomy, U. of Ill., Urbana, Ill. 61803

APS Mtg., Pasadena Ex. Sec., APS., Columbia U.,New York, N.Y. 10027

134 Ann. Mtg., New York AAAS, 1515 Mass. Ave.N.W., Wash., D.C. 20005

ACS Ann. Winter Mtg., New Orleans A. T. Win-stead, ACS, 1155 16th St. N.W., Wash., D.C. 20036

Spring Mtg., ASTM, Atlantic City T. A. Marshall,Jr., ASTM, 1916 Race St., Philadelphia, Pa. 19103

APS Mtg., Chicago Ex. Sec., APS., Columbia U.,New York, N.Y. 10027

Optical Society of America Spring Mtg., Wash., D.C.M. E. Warga, OSA, 1155 16th St., N.W., Wash.,D.C. 20036

APS Mtg., Wash., D.C. Ex. Sec., APS, ColumbiaU., New York, N.Y. 10027

103rd Semiann. Conf. SMPTE, Los Angeles Ex.Sec., 9 E. 41st St., New York, N.Y. 10017

11th Congr. Internatl. Soc. Photogrammetry, Lau-sanne Gen. Sec., Eidgenossische Landestopographie,Seftigenstr. 264, Bern-Wabern, Switzerland

SPSE Ann. Conf., Sheraton-Boston, Boston SPSE,Main P.O. Box 1609, Wash., D.C.

ASTM 71st Ann. Mtg. and 18th Materials TestingExhibit, Statler-Hilton Hotel, San Francisco 1916Race St., Philadelphia, Pa. 19103

1-7 4th European Regional Conf. on Electron Micro-scopy, Rome D. S. Bocciarelli, Istituto Superioredi Sanita, Viale Regina Elena 299, Roma, Italy

3-7 23rd Ann. Symp. on Molecular Structure and Spec-troscopy, Columbus K. N. Rao, Dept. Phys., OhioState U., 174 W. 18th Ave., Columbus, Ohio 43210

4-6 Internatl. Conf. on Electrophotography, RochesterW. L. Hyde, Inst. of Optics, U. of Rochester, Roches-ter, N. Y. 14627

)ctober8-11 Optical Society of America, 53rd Ann. Mtg., Pitts-

burgh Hilton M. E. Warga, OSA, 1155 16th St.,N.W., Wash., D.C. 20036

20-25

28-31

104th Semiann. Conf. SMPTE, Wash., D.C. Ex.Sec., 9 E. 41st St., New York, N.Y. 10017

ISA Ann. Instrument-Automation Conf. and Exhibit,Coliseum, New York, N.Y. D. R. Stearn, ISA,Penn Sheraton Hotel, Pittsburgh 19, Pa.

Autumn 7th Internatl. Conf. on Microwave and OpticalGeneration and Amplification, Hamburg Nach-richtentechnische Gesellschaft im Verband DeutscherElektrotechniker

31-Nov. 2 SPSE Ann. Symp., Wash., D.C. SPSE, Main P.O.Box 1609, Wash., D.C.

December26-31

1969Spring

April20-25

May12-16

June22-27

October

135th Ann. Mtg. AAAS, DallasAve. N.W., Wash., D.C. 20005

Optical Society of America Spring Mtg. El Cortez,Hotel, San Diego. M. E. Warga, OSA, 1155 16thSt. N.W., Wash., D.C. 20036

105th Semiann. Conf. SMPTE, Miami Beach D.Courtney, 9 E. 41st St., New York, N. Y. 10017

SPSE Ann. Conf., Los Angeles SPSE Main P.O.Box 1609, Wash., D.C.

ASTM 72nd Ann. Mtg., Atlantic CitySt., Philadelphia, Pa. 19103

? Optical Society of America, 54th Ann. Mtg. M. E.Warga, OSA, 1155 16th St. N.W., Wash., D.C.20036

19-24 106th Semiann. Conf. SMPTE, Los Angeles D. A.Courtney, 9 E. 41st St., New York, N.Y. 10017

30-Nov. 1 SPSE Ann. Symp., Wash., D.C. SPSE, Main P.O.Box 1609, Wash., D.C.

1970March

April12-17

26-May 1

Optical Society of America Spring Mtg., Wash., D.C.M. E. Warga, OSA, 1155 16th St. N.W., Wash.,D.C. 20086

SPSE Ann. Conf., New York City SPSE, Main P.O.Box 1609, Wash., D.C.

107th Semiann. Conf. SMPTE, Chicago D. A.Courtney, 9 E. 41st St., New York, N. Y. 10017

October? Optical Society of America, 55th Ann. Mtg. M.

E. Warga, OSA, 1156 16th St. N.W., Wash.: D.C.20036

4-9 108th Semiannual Conf. SMPTE, New York D. A.Courtney, 9 E. 41st St., New York, N.Y. 10017

21-24 SPSE Ann. Symp., Wash., D.C. SPSE, Main P.O.Box 1609, Wash., D.C.

FUTURE MEETINGSOPTICAL SOCIETY OF AMERICA1967 11-13 October, 52nd Annual Meeting,

Sheraton Cadillac Hotel, Detroit.

1968 12-15 March, Spring Meeting,Shoreham Hotel, Washington, D.C.

8-11 October, 53rd Annual Meeting,Pittsburgh-Hilton Hotel, Pittsburgh, Pa.

1969 Spring Meeting,El Cortez Hotel, San Diego.

1090 APPLIED OPTICS / Vol. 6, No. 6 / June 1967

AAAS, 1515 Mass.

1916 Race

December5-7

18-20

26-30

1968January7-12

28-Feb. 2

29-Feb. 1

March12-15

22-25

22-27

June8-20

10-14

23-28

September