DescriptionThree-arm circular protractor made for the U.S. Navy; no. 7136-1942. Made by Keuffel & Esser Co., New York, no date, probably 1942. Transparent (slight yellow cast) celluloid plastic with markings in black; 2 brass clamps with molded black plastic knobs. Dial 12-1/8" diameter with one fixed arm 19-1/2" high; two adjustable arms 13-1/2" long x 3-1/4 overall width. The base arm and adjustable arms have a hang hole in a common position for hanging storage. Brass center pivot has a hole for marking or pinning the instrument in place; each arm has three pencil holes along black line for scribing a fixed diameter arc, but there are no scales marked on the arms. With: custom shaped wood storage tray, 12-3/4" wide x 20-3/8" long x 13/16" high, with masonite base; three fixed wood blocks to hold instrument in place. Typewritten label inside tray: Please Return Protractor to Case Each Time After Being Used. One edge is damaged which may have been an attachment point for any cover or lid; no cover is present. Two holes in masonite in tapered area where it appears it could be screwed to wall; the wood edge at the very top has another through hole. This device was typically used for determining a ship’s position using sextant angles. It also had applications in firing range plotting. Also known as a station pointer. See notes. A non-catalog model (number 7136 is not in catalog sequences of the period) produced under contract with the Bureau of Ships for World War II military service. K&E had their main office and factories in Hoboken at this time including U.S. Navy offices and personnel on site. K&E logo and griffin trademark do not appear on the item. No marks of any type on tray. Dial scale reads 0 to 180 degrees in both left and right directions; the left side only has an additional inner scale for 180-360 degrees. Labeled on dial: Keuffel & Esser Co. N.Y. U.S. Navy, Bu. Ships, [symbol 'N' in oval] No. 1736-1942 K&E Xylonite brand plastic did have a yellow tint, but this item is not marked with that brand name.