1895: Otto Steiger receives a patent for his Millionaire calculating machine. It may not have been fruitful, but it multiplied.

The history of calculators stretches back to the invention of the abacus around 2500 B.C. through early attempts by mathematicians like Blaise Pascal and various 19th-century machines, including Charles Babbage's famous difference engine. By the late 19th century, some of these mechanical wonders could add and subtract, but could only simulate multiplication through repeated addition.

Steiger, a German who lived in Munich, invented his machine in 1893. It advanced the ideas of Ramón Verea's 1878 U.S. patent and León Bollée's 1889 French patent. Neither had put his invention into commercial production. Verea just wanted to "show that a Spaniard can invent as well as an American," and Bollée – who lived in Le Mans – turned his efforts to building race cars.

The Millionaire used a complicated internal clockwork of carriage, cranks, cams, cogs, gears, levers, pins, shafts and sliders to perform addition, subtraction, multiplication and division. For multiplication, each turn of the handle read a metallic multiplication table in Braille-like fashion to create a partial product. The device could carry 10s, so you turned the handle a second time for two-digit multipliers, three times for three digits, and so on.

Hans W. Egli of Zurich, Switzerland, manufactured 4,655 of the calculators (with the German name of Millionär) over a remarkable 40-year span for customers in Europe and America. Although it was developed for business calculations, scientists also found it very useful, and government agencies became the prime customers.

The price depended on whether you wanted a hand-operated or electric lever, or an upgraded model with a keyboard, which could likewise be either hand-operated or electric. U.S. prices in 1924 ranged from $475 all the way up to $1,100 ($5,900 to $13,750 in today's money).

The inside of the wooden case had extensive printed instructions and a special cleaning brush to keep the works free of dust and grit. At 100 to 120 pounds each, the Millionaire was a far cry from the first Texas Instruments pocket calculators of 1972 or the keychain calculators given away as promotional swag today.

(Source: Various)