Accession Number: 2011.ph.556
Short brass cylindrical cap with hole through the centre, with rotating disc attached to its top surface. Disc rotates so that a series of holes decreasing in size successively pass over the central hole in the cap.
Primary Materials: Copper alloy
Markings: W-LADD LONDON
Dimensions (cm): 3x10x13
Function: For use in optical experiments.
Good/Fair. Some scratches and spots of corrosion on the top of the cap surface and disc.
Associated Instruments: 2011.ph.557
Manufacturer: W. Ladd London
Date of Manufacture: Ca. Late 19th Century
University of Toronto Physics Department.