Antique Measuring Instrument Collection - Armstrong Scale

This plastic scale bears the promotional advertisement of the Kontite company, an UK manufacturer of compression fittings and cast gunmetal in the 1960s. According to the 1921 edition of the Dictionary of British Scientific Instruments, the so called Armstrong Scale is "A drawing scale, containing a set of eight scales, used chiefly by engineers." The eight scales are normally engraved on the front and the back face of the scale, and they are, respectively, 1/2, 1, 1/4, 1/8, and 3/8, 3/4, 1 1/2, 3, of an inch. However, what make the presented scale unique is that it consists of a patented "Andy-Square," a slider-crank type adjustable set square/protractor which can be used for measuring or drawing inclined lines from zero to ninety degrees.

Front Face  | Back Face