Title

Baldwin Calculating Engine

Description

This is the U.S. Patent Office model for a printing pinwheel calculating machine patented by Frank S. Baldwin of St. Louis, Mo., in 1875. The machine has a brass base, two open brass pieces on each side that form a frame, and a brass, steel, and wooden mechanism. A cylindrical drum mounted horizontally on the frame is 11.5 cm. (4-1/2”) in diameter and 5 cm. (2”) in height.
Both ends of this drum are perforated with six round holes. The drum slides along the shaft into a series of position and may be fixed in place by a small lever. Along the surface of the drum are three slots in which levers slide. The levers may be set at any digit from 0 to 9. Moving a lever from 0 to a given number moves a steel arc that pushes the corresponding number of pins above the surface of the cylinder opposite the lever. Rotating the large cylinder rotates a series of intermediate wheels in proportion to the number of raised pins.These wheels are linked to a set of seven cogwheels, each having ten teeth. On the outer edge of each tooth is a number in type, the numbers ranging from 0 to 9. These cogwheels are linked to a second set of three larger cogwheels that also have digits in type. These wheels may be intended to indicate the multiplier. The front of the two sets of type-wheels has a brass cover that contains a manually operated printing mechanism. The machine has no paper or ribbonThe machine is marked on the large cylinder next to the slots for the three levers: F.P. Baldwin (/) St. Louis, Mo.Baldwin applied for his patent September 8, 1873. A few examples were manufactured and sold by the Reliance Machine Works of Philadelphia.Compare to a production model of the machine, MA.310229.References:U.S. Patent 159244, February 2, 1875.“Baldwin’s Arithmometer,” Philadelphia, Reliance Machine Works, about 1875.P. A. Kidwell, “The Adding Machine Fraternity at St. Louis: Creating a Center of Invention, 1880–1920,” IEEE Annals of the History of Computing, 22 #2 (April–June 2000), pp. 4–21.

Creator

Baldwin, Frank S.

Subject

Mathematics

Medicine and Science

Medium

steel (overall material)
brass (overall material)wood (overall material)

Format

jpeg

Date

1875

Source

National Museum of American History

Identifier

"ID NUMBER
MA.252698"