Rectangular ivory protractor. Recto-protractor scale, 0-180 degrees by one degree then 180-0 degrees by ten degrees. Simply-divided scales for 1/4, 1/2, 3/4, and one inch on 3 1/2-inch section. At bottom, a line of chords, 0-90 degrees, by one degree. Lower edge is bevelled. Verso-simply-divided scales, parts/inch for 60, 50, 45, 40, 35, and 30. First increment divided by ten. Scale of chords, 0-90 degrees by one, is attached to 60 line. Bottom half has double diagonal scale, 1/2 inch and 1/4 inch, 0-7 and 0-13 by ones, respectively, with 10 x 10 grids.
