556 
PHILOSOPHICAL SOCIETY OF WASHINGTON. 
Mr. J. Elfreth Watkins read a paper on The Beginnings of 
Engineering. 
Published in the proceedings of the American Society of Civil 
Engineers, May, 1891. 
Mr. J. Howard Gore read a paper on The Decimal System 
of the Seventeenth Century. 
Published in the American Journal of Science, January, 1891, 
3d ser., vol. 41, pp. 22-27. 
359th Meeting. November 22, 1890. 
Vice-President Gilbert in the chair. 
Thirty-four members present. 
Mr. Charles F. Marvin read a paper on Wind Pressures and 
the Measurement of Wind Velocities. 
Substance published in the Engineering Journal December 13, 
1890, p. 520; also in American Meteorological Journal for Feb¬ 
ruary, 1891, p. 487. 
Mr. William PIallock made a communication on The Coeffi¬ 
cient of Expansion of Some Rocks. 
Published in U. S. Geological Survey Bulletin No. 78, pp. 
109-116. 
360th Meeting. December 6, 1890. 
Vice-President Gilbert in the chair. 
Forty-nine members present. 
Mr. E. G. Fischer read a paper on Standard Screws and 
Threads. 
Not published. 
Mr. Gilbert Thompson communicated An Example of Work 
in Barometric Hypsometry. 
Not published. 
