SMITHSONIAN MISCELLANEOUS COLLECTIONSVOLUME 131, NUMBER 1
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LEADING OPERATIONS OF THESMITHSONIAN ASTROPHYSICALOBSERVATORY, 1895 to 1955
ByC. G. ABBOTResearch Associate, Smithsonian Institution
(PUBUCATION 4222)
CITY OF WASHINGTONPUBLISHED BY THE SMITHSONIAN INSTITUTIONSEPTEMBER 22, 1955
P.
BiLTIMORB, IIS., n. B. A.
LEADING OPERATIONS OF THE SMITHSONIANASTROPHYSICAL OBSERVATORY,1895 TO 1955By C. G. AbbotResearch Associate, Smithsonian InstitutionINTRODUCTIONHaving been associated with the Astrophysical Observatory almostfrom its inception in 1890, it seems good to me to print, in small com-pass in one place, references to the leading researches and instrumentaldevelopments carried out there. It may well be that there are now,and will be in future, those who, for one reason or another, may wishto refer to these events, and will appreciate having easy access to theoriginal sources.The list is far from exhaustive, either as regards the work of theAstrophysical Observatory, or references to it. But I believe it is suffi-cient to present a fair picture of what has been accomplished.SECTION APart i.—Improved and new instruments
1. The bolometer rebuilt and equipped Annals of the Astrophysical Observa-with a balancing device close be- tory,'^ vol. i, pp. 47-56, 105-109,side it and at constant tempera- 1900; vol. 3, p. 42, 1913.ture. Result : The drift nearlyeliminated and the wigglegreatly reduced.2. Galvanometer. Theory investi- Astrophys. Journ., vol. 18, No. i, Julygated and new galvanometer of 1903.tenfold sensitiveness built. Annals, vol. 1, pp. 244-252, 1900.3. Vacuum bolometer with self-con- Annals, vol. 4, pp. 45-64, 1922.tained Wheatstone bridge built.Result : Several-fold increase ofsensitiveness, and increasedsteadiness.4. Silver-disk pyrheliometer invented. Smithsonian Misc. Coll., vol. 56, No.About 100 copies have been 19, 191 1.
1 Hereafter referred to simply as "Annals."SMITHSONIAN MISCELLANEOUS COLLECTIONS, VOL 131, NO. 1
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I
built, standardized, and sold atcost to observers throughout theworld. Repaired at cost andrestandardized free whendamaged.5. Water- flow and water-stir stand-ard pyrheliometers invented andused. The world's scale of solarradiation measurements rests onthem.
2
6. Pyranometer invented. Used dailyon short-method solar-constantobservations. Used by Moore inNorth Carolina and Chile.Copies made and sold at costworld-wide.7. Honeycomb pyranometer, or meli-keron, invented. Used by Ab-bot and Aldrich on human body,and by Sverdrup in polar re-gions. Copies made and soldat cost world-wide.8. Balloon recording pyrheliometerinvented and used at high alti-tudes.9. Two-mirror coelostat invented.10. Slide-rule extrapolator invented.Constantly used in long-methodsolar observing.11. High-power lamp and other de-vices prepared by F. E. Fowlefor researches on deep infraredspectrum.12. Highly sensitive radiometer in-vented for measuring energyspectra of stars.
13. A prism of nearly normal wave-length dispersion invented.
14. The kampometer invented, ahighly sensitive instrument formeasuring radiation.IS- The periodometer invented, a me-chanical instrument for discov-ering pcricKiic changes in data.16. A multiple rotating-sector dia-
Annals, vol. 3, pp. 47-52, 1913; vol. 7,p. 105, 1954.Smithsonian Misc. Coll., vol. 95, No.23, 1937; vol. Ill, No. 14, 1949.Annals, vol. 3, pp. 52-72, 1913; vol. 7,pp. 99-101, 1954-Smithsonian Misc. Coll., vol. 87, No.15. 1932; vol. no. No. II, 1948.Smithsonian Misc. Coll., vol. 66, No. 7,1916.Annals, vol. 4, pp. 65-84, 1922; vol. 7,pp. 15-16, 21, 138, 1954.
Smithsonian Misc. Coll., vol. 72, No.13, 1922.Annals, vol. 4, pp. 41, 300, 1922; vol.5, pp. 43-45, 1932.
Smithsonian Misc. Coll., vol. 65, No. 4,1915-Annals, vol. 4, pp. 347-365, 1922.Annals, vol. 2, pp. 22-23, 2II, 1908.Annals, vol. 4, pp. 84-86, 1922.
Annals, vol. 4, pp. 23-25, 274-287, 1922.
Astrophys. Journ., vol. 69, pp. 293-311,1929.Smithsonian Misc. Coll., vol. 104, No.14, 1945.Astrophys. Journ., vol. 11, No. 2, pp.135-139. March 1900.Smithsonian Misc. Coll., vol. 104, No.22, 1946; vol. 107, No. 19, 1948.Smithsonian Misc. Coll., vol. 89, No. 3,1933-Smithsonian Misc. Coll., vol. 87, No. 4,1932.Annals, vol. 5, p. 96, 1932.
2 A. P.O. modified form of Angstrom pyrheliometer is used in daily observa-tions. See .'Xnnals, vol. 6, pp. 50-55, 1942.
NO. I ASTROPHYSICAL OBSERVATORY, 1895 TO I955—ABBOTphragm combination invented,instantly exchangeable, for bo-lometer work.17. A continuously variable rotatingsector invented, of accurateratio, for photometry.18. A pair of telephoto cameras in-vented, electrically connected,for simultaneous exposure onflying objects. The inventioncomprises a belt-focal-planeshutter, surrounding film spools.Shutter and spools operated bya long spring and clockwork.The observer and assistant sepa-rated by a measured base linekeep both cameras trained. Ob-server makes a series of expo-sures by a trigger, and secondcamera is simultaneouslyexposed.19. Apparatus invented for prevent-ing "personal equation" in ob-serving sudden phenomena. Theobserver notes the sector where,not the times when, the eventoccurs.20. Automatic recording radiationinstruments invented.
No published description.
One camera on public exhibition inLangley case in the West Hall ofthe Arts and Industries Building,Smithsonian Institution.
Apparatus on public exhibition inLangley case (see above).
Annals, vol. 7, pp. 144-146, 1954.
Past 2.
—
Various itwentions, mainly for military use in World Wars I and IIVariable-speed power-transmis-sion mechanism, Claim i, al-lowed "The combination of adriving element, a driven ele-ment, and means for establish-ing, and maintaining constantly,exactly and positively, a desiredspeed ratio between said ele-ments, or for continuously vary-ing said ratio."Variable-speed governor. For aclockwork to be of speed variedat will, without stopping, andcontinuously, through a several-fold range. Used for a Navyproject.Self-propelled rotating projectilefor smooth-bore guns. Combina-tion with smooth-bore ordnance.
U. S. Patent No. 893416 of July1908. 14,
U. S. Patent No. 2367254 of Janu-ary 16, 1945.
U. S. Patent No. 1380172, and U. S.Patent No. 1380171, both of May 31,1921.
SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I3I
8.9-10.
Gyroscopic navigation instrument.For measuring differences inlongitude and latitude withoutsun or star observations.Compass and magnetic-dip indi-cator. Both this and No. 4used the principle of neutralflotation in liquid, and electriccurrent therethrough for operat-ing. Germans independently dis-covered the mathematical prin-ciple of No. 4 and built such amachine but it failed. An Eng-lishman from National Labora-tory examined patent of No. 4,and said it carried superior fea-tures. Work on it stopped withthe Armistice, November 1918.Instrument for navigating air-planes by daylight star observa-tions. Stars can be seen with asmall telescope in daylight ifthe telescope field contains thestar image. The instrumentcould be set to contain the starin its field before observing.Twelve -Stars and two planetswere easily observed by W. H.Hoover in New Mexico. E. D.McAlister observed Altair fromairplane at 21,000 feet.Instrument for automatic mappingof airplane course over ocean,to enable return to course ofmother ship. The patent, No.2367254, above cited, was a partof this device.Solar distilling apparatus.Solar heater.Solar heat collector.
General Electric Patent No. 1501^to C. G. Abbot July 15, 1924.
General Electric Patent No. 1533683to C. G. Abbot April 14, 1925.
Built and tested secretly. Never pub-lished.
Built and tested secretly. Never pub-lished.
Patent No. 2141330, December 27, 1938.Patent No. 2247830, July i, 1941.Patent No. 2460482, February i, 1949.SECTION BPart i.—Researches
I. Bolometric map of infrared solarspectrum.
2. Dispersion of rock-salt and fluo-rite. (Six-place decimals in re-
Annals, vol. I, pp. 5-204, 1900; vol. 5,p. 54. 1932.Smithsonian Misc. Coll., vol. 82, No. i,1929.
-Annals, vol. i, pp. 219-237, 253-262,1900.
NO. I ASTROPHYSICAL OBSERVATORY, 1895 TO I955—ABBOT
fractive index called ridiculousby Holland physicists. Identicalin fifth place with Paschenwork, however.)3. Structure of water-vapor bandswi and wj.4. Total solar eclipses, 1900, 1901,1908, 1918, 1919.
5. Theory of sensitive galvanometer.
6. "The cheapest form of light."7. Solar-constant and solar-distribu-tion work, begun in 1902.8. Mount Wilson expeditions, begun1905.9. Theory of atmospheric transmis-sion.10. Methods for measuring the solarconstant.11. Transmission of the spectrobo-lometer.12. Pyrheliometry.
13. Details of solar-constant observ-ing.14. Sources of error in solar-constantwork.
15. Solar-contant results of stationscompared.
16. Normal solar-energy curves. Pre-ferred determination.
17. Sun's temperature.
18. Atmospheric transmission, manystations, sea level up to 14,000feet altitude.
19. Theory of vacuum bolometer, cor-rected later.
Annals, vol. i, pp. 263-264, 1900.
Astrophysical Observatory specialeclipse volume, 1900.Annals, vol. 2, p. 2, 1908; vol. 3, pp.3-6, 1913; vol. 4, pp. 29, 31, 34, 35,1922.Smithsonian Misc. Coll., vol. 69, No. 9,1 91 9.Annals, vol. I, pp. 244-252, 1900.Astrophys. Journ., vol. 18, No. i, July1903.Annals, vol. 2, p. S, 1908.Annals, vol. 2, pp. 2, 3, 21-82, 211-228,1908.Annals, vol. 2, pp. 7, 83-116, 1908.
Annals, vol. 2, pp. 13-17, 1908.
Annals, vol. 2, pp. 17, 57, 1 17-124, 1908.
Annals, vol. 2, pp. 24, 51, 52, 1908.
Annals, vol. 2, pp. 34-49, 1908; vol. 3,pp. 47-72, 1913 ; vol. 7, pp. 21-23, 1954-Annals, vol. 3, pp. 21-29, 1913; vol. 6,pp. 43-81, 1942.Annals, vol. 2, pp. 58-82, 1908 ; vol. 4,pp. 161-176, 1922; vol. 5, pp. 110-131,1932; vol. 6, pp. 33-42, 1942.Annals, vol. 2, pp. 85-98, 1908; vol. 3,p. 134, 1913; vol. 4, PP- 177-182,1922; vol. 5, pp. 244-245, 1932; vol.6, p. 163, 1942.Annals, vol. 2, pp. 104-106, 1908.Smithsonian Misc. Coll., vol. 74, No. 7,1923.Annals, vol. 2, pp. 106-107, 1908; vol.3, pp. 194-201, 1913.Annals, vol. 2, pp. 96-98, I10-I12,1908; vol. 3, pp. 104-I13, 1913; vol.4, pp. 131-158, 1922; vol. 5, pp. 168-193, 1932 ; vol. 7, pp. 95-98, 1954.Annals, vol. 4, pp. 45-64, 1922; vol. 5,pp. 75-81, 1932.
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20. Infrared and ultraviolet correc- Annals, vol. 5, PP- 103-110, 1932.tions for solar-constant work.21. Solar variation : Astrophys. Journ., vol. 19, p. 305, June1904.a. First suspected. Annals, vol. 2, pp. 98-103, II7-I79,1908.b. Clayton's contributions. Annals, vol. 4, PP- 36, 185, 367-3741922.
c. From solar-constant work Annals, vol. 5, pp. 246-269, 1932.1 920- 1 930.d. Short up and down trendsand ( I ) temperatures,(2) ionosphere.e. Accompanying (i) hurri-canes, (2) magneticstorms,f. Accompanying sunspots.
(i) Smithsonian Misc. Coll., vol. 95,Nos. 12 and 15, 1936; (2) vol. 104,No. 13, 1945-(i) Smithsonian Misc. Coll., vol. no,No. I, and (2) No. 6, 1948.Smithsonian Misc. Coll., vol. no, No.6, 1948.Annals, vol. 7, pp. 165-168, 1954.(i) Smithsonian Misc. Coll., vol. 104,
^>o. 3, 1944; vol. 116, No. 4, 1951
;
(2) vol. Ill, No. 13, 1949.h. Long periodic and weather. Smithsonian Misc. Coll., vol. 122, No.4. 1953-Smithsonian Misc. Coll., vol. 122, No.4. 1953-Smithsonian Misc. Coll., vol. 128, No.4. 1955-Smithsonian Misc. Coll., vol. 128, No.3. 1955-23. Defense of our solar-constant Annals, vol. 4, pp. 3.-'3-366, 1922.value (Abbot, Fowle, Aldrich).24. Brightness of the night sky. Astron. Journ., vol. 27, No. 3, pp. 17-24, June 20, 1 911.25. Direct and scattered radiation of Astron. Journ. vol. 28, No. 16, pp. 129-sun and stars. 135, March 1914.26. Tower telescope on Mount Wilson Annals, vol. 4, pp. 217-257, 1922.and solar-drift curves. Smithsonian Misc. Coll., vol. 78, No. 5,1926.27. Nature of the sun's sharp Scientia, vol. 19, pp. 171-181, March
g. Periodic— (i) 27-day, (2)6.6485-day.
22. A large family of periodic variations:a. In the sun.
b. In the weather.
boundary.
28. Volcanoes and climate.
29. Summary of the work of the As-trophysical Observatory, 1890-
1 920.30. Radiometer measurements of stel-lar-energj' spectra.
1916.(See also Abbot, C. G., "The Sun,"1911.)Smithsonian Misc. Coll., vol. 60, No.29. 1913; vol. 65, No. 9, 1916.Annals, vol. 5, pp. 1-5, 1932.
Astrophys. Journ., vol. 50, pp. 87-107,1924.Astrophys. Journ., vol. 69, pp. 293-311,1929.
NO. I ASTROPHYSICAL OBSERVATORY, 1895 TO 1 955—ABBOT
31. Campaign of observations of solarintensity on surfaces of differentorientations and with variousspectral regions, made at armycamps for Quartermaster Corps,for a period of 8 years.22. Daily solar-constant values, 1920-1952, with 1 0-day and monthlymeans.2Z. Convenient table for solar-constanttabulations. lo-day and monthlymean excesses over 1.900 inhundredths percentages of 1.94.Thus 1.950 becomesI.950-I-900X 100 = 2.58.1.94Similarly 1.940 becomes 2.06.This difference, 0.52, is 0.53 per-cent of mean solar constant.Note.—The tables in the tworeferences cited above areprinted without the decimalpoint for economy, and do notcorrespond with the descrip-tions above unless this factis known.
Annals, vol. 7, pp. 144-164, 1954,
Annals, vol. 5, pp. 177-182, 1932; vol.6, pp. 85-162, 169-175, 1942; vol. 7,pp. 26-94, 1954.Smithsonian Misc. Coll., vol. 117, No.10, pp. 20-24, 1952; vol. 128, No. 4(table i), 1955.
Part 2.
—
Work of specialistsL. B. Aldrich
:
a. The melikeron, an approxi-mately black-body pyra-nometer.b. Reflecting power of clouds,and earth's albedo.c. Eclipse expedition, June1 91 8.d. A study of body radiaticHi.
e. Sun spots and the solar con-stant.f. Various researches onlong-wave rays.g. Author (with W. H.Hoover) of volume 7 ofAnnals of the Astro-physical Observatory.F. E. Fowle:a. On atmospheric precipita-ble water.
Smithsonian Misc. Coll., vol. 72, No.13, 1922.Annals, vol. 4, pp. 375-381, 1922.Smithsonian Misc. Coll., vol. 69, No. 9,1919.Smithsonian Misc. Coll., vol. 81, No. 6,1928.Annals, vol. 7, pp. 165-168, 1954.Annals, vol. 4, pp. 287-299, 1922.Annals, vol. 7, 1954.
Astrophys. Journ., vol. 35, p. 149,1912.
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b. On Avogadro's number.c. On atmospheric ozone.
d. On water-vapor absorptionabove 3 microns.e. On water-vapor absorptionbelow 3 microns.f. Preparation of PhysicalTables.
3. W. H. Hoover:Besides his large part in vol-ume 7 of the Annals ofthe Astrophyical Observa-tory, as coauthor with L. B.Aldrich, he engaged in clas-sic researches on photosyn-thesis as a member of thestaff of the Division ofRadiation and Organisms,later a branch of the Astro-physical Observatory.a. Carbon-dioxide assimilationin a higher plant (withEarl S. Johnston andF. S. Brackett).b. The dependence of carbon-dioxide assimilation in ahigher plant on wave-length of radiation.c. Improvements in use ofstandard water-flow pyr-heliometer, and in silver-disk pyrheliometer.d. Special studies of globalsun and sky radiation(with L. B. Aldrich).e. Mechanical integrator forBrown recording poten-tiometer.
Astrophys. Journ., vol. 40, p. 435, 1914.Smithsonian Misc. Coll., vol. 81, No.II, 1929.Annals, vol. 3, pp. 171-193, 1913.Annals, vol. 4, pp. 274-287, 1922.Smithsonian Physical Tables, 5th ed.,1910; 6th ed., 1914; 7th ed., 1919;8th ed., 1934.
Smithsonian Misc. Coll., vol. 87, No.16, pp. I -19, January 16, 1933.
Smithsonian Misc. Coll., vol. 95, No.21, pp. 1-13, February 27, 1937.
Smithsonian Misc. Coll., vol. 122, No.5, pp. i-io, August 14, 1953.Annals, vol. 7, pp. 99-104, 1954.
.\nnals, vol. 7, pp. 144-164, 1954.
Annals, vol. 7, pp. 138-139, 1954.