ALTER : RAIXFALL AND SUN-SPOT PERIODS. 33 



of the Graduate School, whose grants for computers have been a 

 very important factor in the prosecution of the work. Mr. Anthony 

 Gates was engaged as computer for the earlier stages of the work 

 and Miss Nellie Lynn for the later. Prof. F. E. Kester has devoted 

 a great deal of time to discussing each phase of the problem, and to 

 his suggestions is due much of the success. Prof. C. F. Talman has 

 loaned me many books from the library of the United States 

 Weather Bureau. Mr. S. D. Flora has thrown open to me all the 

 records in the state meteorological office at Topeka. Prof. Carl 

 Ryder has sent me a great deal of manuscript matter, which has 

 been extremel}^ valuable. The Governor General of Madagascar 

 sent manuscript tables of rainfall and temperature at Tananarive. 

 The Egyptian government sent valuable manuscript records of Sou- 

 dan and Abyssinia, which unfortunately do not extend back far 

 enough for present uses. Supplemented by the next ten years' rec- 

 ords, they will be very valuable. Meteorologists of several other 

 countries have sent all available printed records. To all these I owe 

 my most sincere thanks. 



BIBLIOGRAPHY. 



la. DocGLASS, A. E.: The Correlation of Sun Spots, Weather, and Tree 

 Growth. Pub. Aruerican Astronomical Soc. 1918, vol. Ill, p. 121. 



lb. Douglass, A. E.: Climatic Cycles and Tree Growth. Carnegie Institu- 

 tion of Wash., 1919. The author seems to have proved definitely a 

 correlation between climate and sun spots. Nothing on this subject 

 that has yet come to my attention begins to compare in importance 

 with this work. 



2. Haxn, J.: Sun Spots and Rainfall. Handbook of Climatology (trans, by 



R. DeC. Ward), vol. I, p. 406. Bruckner: KUmaschwankungenseit, 

 1700 ("\'ienna, 1890). Has shown a varying period of about thirty-five 

 years in rainfall and temperature. Lockycr: The Solar Activity. 1833- 

 1900. Proc. RoA\ Soc, vol. 68, p. 285. Showed a possible correlation of 

 this period with sun spots. C lough, H. W.: Synchronous Variations in 

 Solar and Terrestrial Phenomena. Astrophys. Jour., vol. 22, p. 42. Has 

 greath- strengthened the evidence of such a relationship. They have 

 also considered the variation in length of the sun-spot period. Clough 

 says: "The solar-spot activity is periodically' accelerated and retarded, 

 and this action is primarily manifest in the varying length of the 

 eleven-year spot cycle, since it operates continuously throughout the 

 entire interval to accelerate or retard the occurrence of the two phases." 

 (Loc. cit., p. 59.) 



3. Turner, H. H.: A Fifteen-month Period in Earthquakes. Monthly No- 



tices, Roy. Astronomical Soc, April, 1919, p. 461. 

 4a. Alter, Dinsmore: Possible Connection Between Sun Spots and Earth- 

 quakes. Science, May 14, 1922, p. 486. 



4b. Alter, Dinsmore: A Possible Rainfall Period Equal to One-ninth the 

 Svm-spot Period. Monthly Weather Review, Feb., 1921. Continua- 

 tion of Investigation of a Possible Rainfall Period Equal to One-ninth 

 the Sun-spot Period, and Application of Marvin's Periodocrite to Rain- 

 fall Periodicitj'. Kansas University Science Bulletin, vol. XIII Nos 

 8 and 9. 



3 — Science Bui.— 3728 



