This is a object with scale in millimeters (0-100) along which a carriage with an indicator line can be slid by turning a knurled knob. Turning the knob clockwise way moves the carriage right, and anti-clockwise moves the carriage to the left. At the rear of the carriage there is another knob that can be used to fix the carriage in place or permit it to move freely. A screw at the front of the carriage has no obvious purpose, but perhaps permits another piece to be attached.
This can be attached to another instrument by two heavy screw bolds on either side of the instrument. On the rear side of the instrument there are two metal strips inside in a black (insulating?) surround. Two paired metal arms rest lightly on each of these strips.
Accession Number: 2019.ast.162
Primary Materials: Metal: Iron Alloy
Dimensions (cm): Length = 18, Width = 10.5
Excellent: The object is in excellent condition. The indentations on the knobs are very slightly rusted. The instrument is slightly smudged.
Date of Manufacture: Mid-Late 20th century
This object was likely moved from the David Dunlap Observatory in Richmond Hill in 2008, upon the sale of the observatory. It was stored at the Department of Astronomy and Astrophysics until 2017, when it was moved to a new storage location in McLennan Physical Laboratories.
Additional Information and References: