TRANSACTIONS OF SCIENTIFIC SECTION. 119 
MARCH 26, 1889—SEVENTY-SECOND REGULAR MEETING. 
Charles B. Warring, Ph.D., chairman, presiding; eight 
members and several guests present. 
Professor L. C. Cooley, Ph.D., addressed the Section 
on ‘‘ Illustrations of Simple Harmonic Motion.”’ 
The subject was fully illustrated by a series of experi- 
ments and by the lantern. 
APRIL 9, 1889—SEVENTY-THIRD REGULAR MEETING, 
Charles B. Warring, Ph.D., chairman, presiding. 
Mr. Edward Elsworth read a paper on 
THE PROGRESS OF PHOTOGRAPHY. 
So common has the camera become ; so familiar are its 
mechanical construction and operations that thousands 
of its votaries doubtless forget, if they ever knew, that 
photography is the outcome of a long line of baffling 
scientific investigations. 
‘* Any one can take pictures.”’ advertises an enterpris- 
ing manufacturer of cameras. ‘‘ All that is necessary is 
to press a button. We do all the rest.”’ 
So there are many who never seek to penetrate the 
mysterious arena of the dark room, and scarcely stop to 
think how a photograph is made. 
Perhaps no art has ever been so thoroughly popular- 
ized as the art of photography. But photography is 
more than a popular art. It is the legitimate child of 
science. It owes its development to years of patient la- 
bor and study of the subtle properties of light and its 
action upon sensitive surfaces. 
Art has popularized it, and established its commercial 
value ; but its victories belong to the laboratory, and its 
future depends upon the experiments and investigation 
of the chemist. 
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