NOV. 19, 1921 proceedings: botanical society 473 



155th meeting 

 The 155th meeting of the Academy was held at the Cosmos Club, the 

 evening of Thursday, March 17, 1921. Dr. A. McL. Nicolson, research 

 engineer of the Western Electric Company, Inc., New York, delivered an 

 address on TJie piezo-electric effect in certain crystals. The address was 

 illustrated with lantern slides, and demonstrations were given of some of the 

 practical applications of the crystals to the transmission and reception of 

 sound. 



156th meeting 



The 156th meeting of the Academy was held jointly with the Biological 

 Society of Washington at the Cosmos Club, the evening of Saturday, April 

 2, 1921. Dr. A. D. Hopkins of the Bureau of Entomology, U. S. Depart- 

 ment of Agriculture, delivered an address entitled Intercontinental problems 

 in nattiral and artificial distribution of plants and animals. In condensed 

 form this has since been published in two papers in the Journal of the Acad- 

 emy: (1) Intercontinental problems in biocliniatics ; with special reference to 

 natural and artificial distribution of plants and animals."^ (2) Bioclimatic 

 zones of the continents; with proposed designations and classification.^ 



157th meeting 



The 157th meeting of the Academy was held at the Cosmos Club the 

 evening of Thursday, April 21, 1921. Dr. C. G. Abbot, Assistant Secretary 

 of the Smithsonian Institution, delivered an address on The solar constant 

 observing stations of the Smithsonian Institution. 



In the course of his lecture the speaker described the studies of solar radia- 

 tion carried out at Washington, D. C; Bassour, Algeria; Hump Mountain, 

 North Carolina; Mount Harqua Hala, Arizona; Mount Wilson, California; 

 Calama, Chile; Montezuma, Chile; and Mount Whitney, California, at 

 altitudes ranging from sea level to 14,500 feet. He summarized results 

 accomplished in perfecting processes of investigation, in the invention and 

 construction of highly precise standardized instruments, and in the securing 

 of simultaneous determinations of the solar constant of radiation at Washing- 

 ton, Mount Wilson, and Mount Whitney; and the bearing of these results, 

 notably with respect to meteorological investigations. The data are brought 

 together in a paper of 20 printed pages, entitled Studying the sun's heat on 

 mountain peaks in desert lands, which will appear shortly in the Appendix 

 to the Report of the Smithsonian Institution for 1920. 



WiLLLf^M R. Maxon, Recording Secretary. 



BOTANICAL SOCIETY 

 150th meeting 



The 150th regular meeting of the Botanical Society of Washington was 

 held in the Assembly Hall of the Cosmos Club at 8 p.m., Tuesday, March 

 1, 1921. 112 members and guests were present. Among the visitors were 

 Dr. Robert F. Griggs of Ohio, Prof. Leo E. Melchers of Kansas, Dr. A. G. 

 Johnson of Wisconsin, Mr. Paul Siggers, about to leave for his new work 

 with Johnston and Carleton in Panama, and IMr. C. VallEJO, Agricultural 

 Attache of the Argentine Republic. In the absence of President Cham- 

 bliss, the meeting was called to order by Vice-President P. L. RickeR- 



2 This Journal II: 223-227. 1921. 



3 This Journal 11: 227-229. 1921. 



