Babbage

Charles Babbage (1791-1871) is widely regarded as the first computer pioneer and the great ancestral figure in the history of computing. Babbage excelled in a variety of scientific and philosophical subjects though his present-day reputation rests largely on the invention and design of his vast mechanical calculating engines. His Analytical Engine conceived in 1834 is one of the startling intellectual feats of the nineteenth century. The design of this machine possesses all the essential logical features of the modern general purpose computer. However, there is no direct line of descent from Babbage’s work to the modern electronic computer invented by the pioneers of the electronic age in the late 1930s and early 1940s largely in ignorance of the detail of Babbage's work.

Babbage failed to build a complete machine. The most widely accepted reason for this failure is that Victorian mechanical engineering were not sufficiently developed to produce parts with sufficient precision.

In 1985 the Science Museum launched a project to build a complete Babbage Engine to original designs to explore the practical viability of Babbage’s schemes. The Engine chosen was Babbage’s Difference Engine No. 2 designed between 1847 and 1849. The calculating section of the Engine, which weighs 2.6 tonnes and consists of 4,000 separate parts, was completed and working in November 1991, one month before the 200th anniversary of Babbage's birth.

The Science Museum has a special relationship with Babbage which predates the construction of the Difference Engine No. 2 . Its collections contain the seminal objects that are the material legacy of Babbage’s endeavours, and its archives hold the most comprehensive set of original manuscripts and design drawings.

Attempts to mechanise calculation in the seventeenth and eighteenth centuries had led to a number of devices to aid arithmetic calculation. Devices by early pioneers - Schickard, Pascal and Leibniz amongst others - were, for all their ingeniousness, ornate curiosities of doubtful reliability unsuited to the demands of routine use.

Until the successful automation of calculation in the twentieth century, scientists, navigators, engineers, surveyors, actuaries and the like relied on printed mathematical tables to perform calculations requiring more than a few figures of accuracy.

The production of tables was not only laborious but also prone to error. A contemporary of Babbage, Dionysius Lardner, wrote in 1834 that a random selection of forty volumes of numerical tables contained no fewer than 3,700 acknowledged errata and an unknown number of unacknowledged ones.

Tables had three basic sources of error: errors of calculation (‘computers’ at that time were human beings who performed the routine calculations), errors of transcription (that arose when the results were copied into a form suitable to give to a printer) and errors of typesetting and printing.

Babbage was a connoisseur of and fascinated by printed tables, his collection of some 300 volumes being one of the most comprehensive in existence. He was a fastidious analyst of tabular errors and his first motive for designing calculating engines was to eliminate the risk of error in the production of mathematical tables. He spent much of his life in pursuit of this ideal.