Antique Drawing Instrument Collection - Adjustable Set Square

As noted in Drawing Instruments, 1580-1980, this type of adjustable set squares were first devised by W. F. Stanley in the 1920s, the one that shown in their 1924 catalogue was made of transparent celluloid with a white setting-arc, which is similar to the one showing here. It is also interesting to note that this form of instrument was unique to Britain until the 1970s.

Fully Opened View  | The Original Card Board Envelop