RECORDS 487 



The Secretary also announced that Professor Henry F. Os- 

 born had been made a Life Member of the Academy. 



The following candidates for resident membership, approved 

 by the Council, were duly elected : 



W. J. Gies, Ph.D., 437 West 59th Street. 

 Charles Henry Davis, 99 Cedar Street. 



Richard E. Dodge, 

 Recording Secretary. 



SECTION OF ASTRONOMY, PHYSICS AND 

 CHEMISTRY. 



May 7, 1900. 



Section met at 8:30 P. M., Prof Wm. Hallock presiding. 



The minutes of the last meeting of Section were read and 

 approved. 



The following program was then offered. 



Bergen Davis, The Bernouilli Effect in Stationary 

 Sound Waves. 



R. W. Wood, Color Photographs and Sound Wave Pho- 

 tographs, Exhibited by Professor Hallock. 



Summary of Papers. 



The experiments described by Mr. Davis were in three groups, 

 those with a sound wave anemometer, those with the use of 

 empty gelatine medicine capsules instead of cork dust to show 

 the Kundt figures, and those concerning the longitudinal motion 

 of a cylinder closed at one end, across the stream lines in a 

 stationary sound wave. 



The stationary sound wave was that produced by a stopped 

 organ pipe, provided with a glass panel for observation, when it 

 was sounding its first overtone. A thin rubber diaphragm near 

 the central node prevented air currents due to the blowing of 

 the pipe. The cups of the miniature anemometer were made by 



