โ Scribed by F.W. Sawyer
No coin nor oath required. For personal study only.
SI,~CTION OF ])HOTOGRAPII "x7 A.ND MIeROSCOPv.--The first stated meeting of the Section was held on Tuesday, March 6th. Dr. Henry Leffmann in the chair.
l'resent, 55 members and visitors. The questions of adopting a code of regulations and nominations for Officers were referred to the Executive Committee, with instructions .to report at the next stated meeting.
Dr. I,effmaun addressed the meeting on the " Theories of Photographic Development." He pointed out that most of the modern developers in photography are benzene derivatives, and partake of the character of that substance in being rather difficult of complete oxidation, and hence exercised restricted reducing action. The localization of the deposited silver upon the impressed portions of the latent image may be due to the difference in electric potential owing to the disturbance in the homogeneity of the film. This condition naturally establishes a polarity which would cause a selective deposition of the silver.
Mr. F. E. 1yes followed with a description of the practical remedies for the difficulties encountered from under-and over-exposure. B,Ir. John G. Baker exhibited and described an ingenious apparatus for determining the time of shutter exposure.
A general discussion followed on methods of preparing lantern slides, ~, W. SAWYt~R, Secretary.
๐ SIMILAR VOLUMES
%',"C/lOte.~. [J. F. l., tion of fundamental electrical units was ch~elt upon and the relatious between primary aml secondary standards described. P-.ICtlARIi l,.