Rectangular drawing instrument in brass
1865
Standard 6" diagonal scale in case; brass 6 7/8" x 3 7/16" screwed by 4 screws to mahogany base with a mahogany cover
Three diagonal scales
1731-1770
Rustless steel scale (40 3/4" x 2 7/10" x 1/8") one bevelled edge divided to 1/10 inch
1929
Diagonal scale, metal 6 1/2" by 2 1/2"
1876
Diagonal scale, screwed to mahogany base
Semi-circular protractor by Henry Sutton
1655
3-foot brass scale
1851-1876