Calculating
History and Origins
C
lculating devices are the tools used to facilitate and accelerate mathematical calculations. They have progressed from simple hand-manipulated beads; to sliding rods; to discs and rules; to mechanical machines; to electro-mechanical devices; and finally to electronic instruments and computers. 
Counting rods, used in Asia and uncovered at archaeological sites, date to the second century B.C. They are small dowels about 6 inches long made of bamboo and other woods. A standard set of counting rods contains 271 rods. Although the earliest written account of an abacus as we generally think of them, with beads that slide along a bamboo rod or later on metal rods, is from the 1500s, it is believed by some historians that the Romans and Chinese were using them by the third century A.D. Remarkably, the abacus is still in use in China and other parts of the world today.
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Sectors & Slide Rules (37)
The oldest known surviving example of a linear slide rule, which was made by inventor Robert Bissaker, dates to 1654. The standardized rectilinear design with scales familiar to us today is based on the Mannheim rule invented about 1853. Slide rules were originally made of brass, ivory or boxwood and later thermoplastics. The grid slide rule was invented by Joseph Everett in 1866. It is flat, rectilinear, and segmented into short parallel rules with an effective length of 40 feet. The Fuller calculator was introduced by George Fuller in 1878. It has an effective 42-foot long scale accurate to within 1 to 10,000 spiralled around a hand-held 3 inch diameter, 12 inch long wood tube. In 1881, Edwin Thatcher designed a tabletop slide rule that bears his name. It too is cylindrical, 4in. in diameter and 18in. long. One of the most popular pocket size, tubular styles, especially in Europe was the Otis King calculator which began production in 1922. The slide rule remained the basic tool of engineers and scientists until introduction of the hand held electronic calculator in 1971. -
Mechanical (21)
About the time the slide rule was becoming the pocket calculator of the scientist, a simple calculating machine was described by Wilhelm Schickard, and in the late 1600s, Gottfried Leibniz introduced a cylindrical geared computing devise that could add, subtract, multiply and extract roots and looks remarkably similar to the mechanical calculating devises of the early to mid-1900s. These devises remained more objects of curiosity than practical tools until 1820 when Charles Thomas invented an arithometer with levers and a geared drum. In 1895, O. Steiger patented a machine that could multiply with one pull of the handle. An arithmetical machine called the Curta consists of a small 2.5 inch diameter, 3.5 inch tall cylinder with a handle on top and vertical adjustable scales along the sides of the cylinder. It is named after its inventor and was perhaps the highest quality small calculator invented. -
Electronic (3)
The unveiling of the transistor in 1948 and invention of the microchip in 1959 led eventually to mass production of inexpensive hand held electronic calculators, beginning in 1971 with Texas Instrument’s pocketronic, rendering the calculating machine and slide rule obsolete virtually overnight. As soon as three years later Hewlett Packard started marketing a programmable pocket calculator and a year later the first personal computer in kit form was introduced. The Apple II hit the stores in 1977 and by the early 1980s desktop computers were becoming commonplace.