/ 
fRocEtfMNGS. 357 
Mr. H. S. Davis spoke by invitation on The state of progress 
on the new reduction of Piazzf’s star observations. [Published in 
Science, vol. xi, p. 578 (1900).] 
Remarks on the communication were made by Messrs. Hay- 
ford, We ad, Radelfinger, Raker, and Shidy. 
Mr. A. Macfarlane presented by invitation a paper on Vector- 
differentiation, read in abstract by Mr. Radelfinger. [Pub¬ 
lished in this volume, p. 73.] 
Remarks were made by Messrs. Baker and Bauer. 
Mr. C. K. We ad read a paper on Certain discontinuous and 
indeterminate functions. [Published in this volume, p. 65.] 
517th Meeting. April 14, 1900. 
President Sternberg in the chair. 
Twenty-one persons present. 
Mr. G. L. Raymond, of Princeton University, read by invita¬ 
tion a paper on Some aesthetic principles of music. [Hot pub¬ 
lished.] 
Mr. R, H. Strother presented a communication on The 
physics of the phonograph. [Hot published.] 
Mr. C. K. We ad read a report on Modern problems in Acous¬ 
tics. [Published in this volume, p. 129; Science, vol xi, p. 732 
(1900).] 
518th Meeting. April 28, 1900. 
Past President Bigelow in the chair. 
Twenty-seven persons present. 
Mr. We ad exhibited some photographs of Compound pendulum 
curves made with rare skill by Mr. W. Iv. Carr, a member of this 
Society. 
Mr. L. J. Briggs read a paper on Adsorption of salts by 
organic and inorganic substances. [Hot published.] 
