This is an extremely rare and properly functioning Burroughs Class 5, 9-column Key-driven Calculator - c1915. Prior to the introduction of electronic calculators, this was your desktop computer. This ~100-year-old machine is just beautiful, it is housed in an elegant die-cast alloy casing. The legs at the rear raise the keyboard to an angle of about 15° and give the machine its distinctive "high-heeled" appearance. No plastic here, it's made of aluminum, steel, and brass. Enter the numbers sequentially to add, and pull the crank to clear the registers. Addition is the only operation directly performed on this Buttoughs. For subtraction, an indirect method of addition is adopted. The keyboard contains large and small figures on each key. The small figures are the machine complements of the large figures, A manual is included which explains how to use the calculator. serial Number: 399068 Dimensions: Width = 10_1/2" / 27 cm Depth = 12 " / 30 cm Height = 5 " / 13 cm Weight: 11 1/2 lbs / 5.2 kg