552 
PHILOSOPHICAL SOCIETY OP WASHINGTON. 
Mr. C. R. Van Hise made a communication on the Pre-Cam- 
brain Rocks of the Black Hills of Dakota. 
Published in Bulletin of the Geological Society of America, vol. 
1, pp. 203-244, 8vo, Washington, 1890. 
35Qch Meeting. March 15, 1890. 
Vice-President Gilbert in the chair. 
Thirty members present. 
Mr. B. E. Fernow read a paper on The Relation of Forests to 
Water Supplies. 
Published by U. S. Department of Agriculture, Report of the 
Chief of the Forestry Division for 1889, pp. 297-330. 
Mr. G. E. Curtis made a communication on The Relation of 
Surface and Climatic Conditions to the Flow of Water-Courses. 
Not published. 
351st Meeting. March 29, 1890. 
President Dutton in the chair. 
Thirty-four members present. 
The President announced the election to membership of Joseph 
Francis James and George Marie Searle. 
The Secretary read a letter from the University of Toronto, 
Canada, giving an account of the losses to the university on Feb¬ 
ruary 14, 1890, by fire and soliciting donations of publications 
for a new library. 
Mr. Marcus Baker read an obituary notice of Edward Brown 
Lefavour. 
Published in this volume, pp. 488-490. 
Mr. O. H. Tittmann read A Note on the Length of Kater’s 
Pendulum. 
Published in Nature April 10, 1891, vol. 41, No. 1067, p. 538. 
