152 ANNALS NEW YORK ACADEMY OF SCIENCES 



observations made by A. Crova/^ at Montpellier, have frequentW been 

 cited as a proof of the decrease of solar radiation due to a purely ter- 

 restrial cause. Curiously enough, the effect of the Krakatoa dust veil 

 on atmospheric temperature seems to have attracted no special attention. 

 Besides the Krakatoa, other volcanoes were very active during the year 

 1883. Of these St. Augustin^^ and Bogoslof^^ of the Aleutian chain of 

 islands, as well as the Ometepe,^^ may be mentioned.^^ The violent 

 eruption of St. Augustin, which occurred on October 6, is of particular 

 interest. St. Augustin is an island south of the Alaskan peninsula 

 (position— 153° 25' W., 59° 18' N.). The explosion split the island 

 in two, from peak to base, while the greater portion of the northern half 

 of the volcano was blown away. 



The study of the temperature data for the year 1902 is also of special 

 interest, not only because during that year the world's volcanic activity 

 was greatly intensified, but also because some of the explosive eruptions 

 v/hich occurred undoubtedly produced a dust veil in the higher layers of 

 the atmosphere. 



A decrease of solar radiation has been observed by Henri Dufour-- in 

 Lausanne, by Harvey N". Davis^^ in Providence, by H. H. Kimball-^ in 

 North Carolina, by S. P. Langley^^ in Washing-ton, by L. Gorczynski^*^ 

 in Warsaw, and this decrease has generally been ascribed to the presence 

 of volcanic haze. 



In 1901 the outbursts of Mt. Colima, Mexico, were more frequent and 

 more intense than during the preceding years. The same was true in 



" A. Ceova : "Sur les observations actinometriqiies faites a Montpellier," Comptes 

 Rendns. . .vol. 106, p. 810. 1888. 



IS George Davidson : "Notes on the Volcanic Eruption of Mount St. Augustin," Science, 

 vol. 3, p. 186. 1884. 



" C. Hart Merriam : "Bogoslof, our Newest Volcano," Harriman Alaska Expedition, 

 vol. 2, p. 291. 1901. 



^ G. Mercalli : Vulcani attivi della terra, p. 356. Milano, 1907. 



^ C. W. C. FuCHS : "Die vulkanischen Ereignisse des Jahres 1883," Min. u. petrogr. 

 Mitth., vol. 6 n. F., p. 185. 1885. 



^ Hexri Dufour : "Sur la diminution du rayonnement solaire," Comptes rendus, vol. 

 36. p. 713. 1903. 



23 Harvey N. Davis : "Observations of Solar Radiation with the Angstr5m Pyrheli- 

 ometer," Monthly Weather Rev., vol. 31, p. 275. 1908. 



^ H. H. Kimball: "Observations of Solar Radiation with the Angstrom Pyrheliometer 

 at Asheville and Black Mountain, N. C.," Monthly Weather Rev., vol. 31, p. 320. 1903. 



See also same author: "Solar Radiation, Atmospheric Absorption and Sky Polariza- 

 tion, at Washington, D. C.," Bull. Mt. Weather Observatory, vol. 3, p. 110. 1910. 



25 S. P. Langley : "On a Possible Variation of the Solar Radiation and its Probable 

 Effect on Terrestrial Temperatures," Astroph. Jour., vol. 19, p. 305. 1904. 



26 Ladislas Gorczyxski : "Sur la diminution de I'intensite du rayonnement solaire en 

 1902 et 1903," Compt. Rend. . . . vol. 138, p. 255. 1904. 



Same author : "Quelques renseignements sur la depression du rayonnement solaire a 

 Varsovie en 1903," Bull. Meteor, du depart, de I'Herault. Montpellier, 1906. 



