X hits on this document





74 / 247



ued to be improved through the nineteenth century and into the twentieth. Eventually they were operated by electric motors, and in 1892,William S. Burroughs developed a machine in which numbers were conveniently entered by keystrokes. Others invented calculators that printed out their numerical results. Such machines quickly be- came staples of business offices and scientific laboratories.

But a better alternative had been available in principle for many decades, the machine conceived by the Englishman Charles Babbage, who from 1828 to 1839 served as Lucasian Professor of Mathematics at Cambridge University, the position once held by Isaac Newton and now occupied by the physicist Stephen Hawking. Babbage was in- spired to think about calculating machines because of his connection with the Royal Astronomical Society, which brought him face to face with the many errors appearing in hand-calculated tables used for astronomical observations. He is said to have blurted out I wish to God these calculations had been performed by steam!and, in 1834, began designing the Analytical Engine.

Babbage had earlier designed what he called Difference Engines for specialized calculations.The Analytical Engine was meant to be far more: a general-purpose computer that could deal with a wide range of mathematical problems.The power of the machine came from its capability to be programmed; that is, it could follow a predetermined set of instructions.The program steps were to be encoded and entered into the machine on punched paper cards like those pioneered in the Jacquard loom. The machine could operate on numbers 40 digits long, each represented by a column containing that many wheels. It would take three seconds to execute an addition, and two to four minutes for a multiplication or division, with final results to be printed out or set in type by the device.

The conception of a calculating device that followed a program, whichproperly formulatedcould solve any conceivable math- ematical problem that had a solution, was a great breakthrough. (The first programmer was Augusta Ada King, Countess of Lovelace, and amusingly enough, daughter of that very same Lord Byron who had inspired Mary Shelley to write Frankenstein. She developed program-

Document info
Document views221
Page views221
Page last viewedSat Oct 22 00:02:59 UTC 2016