How it began
Abraham Jakub Stern was born in Hrubieszów, in what is now south-eastern Poland, and trained as a watchmaker. The reformer Stanisław Staszic noticed him at a clockmaker's shop around 1800 and sent him to Warsaw to study. Around 1810 Stern designed his first computing machine, and in 1811 he sent Staszic a report asking for funds. He presented a machine for the four arithmetic operations to the Warsaw Society of the Friends of Science in January 1813, a machine for square roots in January 1817, and a combined machine after that.
Before it existed
Stern argued that many mechanical tools had been invented to spare the body, but few to relieve the mind. He considered calculation a necessary mental labor in which multiplication and division were most prone to error. He also noted that checking a sum by reversing it only tests one mental act with another, which can hide a mistake.
How it works
Stern described the combined machine as a long rectangular box with five rows of wheels. The top row held 13 number wheels read through small openings. Below it a sliding carriage carried two more rows with folding cranks and a main crank. A handle switched the machine between arithmetic and root extraction, and others set it for addition and multiplication or for subtraction and division. In multiplication the carriage stepped across by itself as the crank turned, and a bell rang when the work was done. Extra rows of Roman numeral wheels let the operator test a result.
Who pushed back
Stern wrote that the war situation of the Polish state and the cost of building in metal made the work harder. Members of the Society did not fully understand the machines. In their view a calculating machine was a clever toy and too expensive to popularize.
What changed first
The machines brought Stern recognition. He became a corresponding member of the Warsaw Society of the Friends of Science in 1817 and a full member in 1830. In 1816 and 1818 he demonstrated his machines to Tsar Alexander I, who granted him an annual pension of 350 rubles. No original Stern machine survives, only a later replica of one of them. Stern's son-in-law Chaim Zelig Slonimski went on to invent calculating machines of his own. Stern died in Warsaw in 1842.
