Similar in design to M-111b. Index arm rotates around large circular hinge that is cut out, giving unobstructed view of center marker for angle measurements. Minute scale on index is labelled "Minutae." Decorative foliate engraving and scalloping on hinge, index, and ends of base. Outer and inner degree scales on protractor ring are connected by transversals, every one degree, for use with minute scale on index arm. Base arm has tab on right for index arm to rest on; upper edge of base is sloped.
