Charles Babbage

More than a century before the first electronic digital computers were invented, British mathematician and inventor Charles Babbage conceived and designed a mechanical “engine” that had most of the key features of modern computers. Although Babbage’s computer was never built, it remains a testament to the remarkable power of the human imagination.
Charles Babbage was born on December 26, 1791, in London, to a well-to-do banking family that was able to provide him with a first-class private education. Even as a young child Babbage was fascinated by mechanisms of all kinds, asking endless questions and often dissecting the objects in search of answers. He became a star student, particularly in math, at boarding school, where he and some intellectually inclined friends stayed up late to study.
In 1810 Babbage entered Trinity College, Cambridge, where he studied advanced calculus and helped found an organization to reform the Newtonian discipline along more modern European lines. By 1815, Babbage had made such an impact in mathematics and science that he had been elected a fellow of the prestigious British Royal Society. His reputation continued to grow, and in 1828 he was appointed Lucasian Professor of Mathematics at Cambridge, occupying the chair once held by Isaac Newton. What was becoming a distinguished career in mathematics then took a different turn, one in keeping with the times. By the early 19th century, the role of mathematics and science in European society was beginning to change. Britain, in particular, was a leader in the Industrial Revolution, when steam power, automated weaving, and large-scale manufacturing were rapidly changing the economy and people’s daily lives. In this new economy, “hard numbers”—the mathematical tables needed by engineers, bankers, and insurance companies—were becoming increasingly necessary. All such tables, however, had to be calculated slowly and painstakingly by hand, resulting in numerous errors.
One day, when poring over a table of logarithms, Babbage fell asleep and was roused by a friend. When asked what he had been dreaming about, Babbage replied that “I am thinking that all these tables might be calculated by machines.” The idea of mechanical computation was perhaps not so surprising. Already the automatic loom invented by Joseph-Marie Jacquard was being controlled by chains of punched cards containing weaving patterns. The idea of controlled, repetitive motion was at the heart of the new industry. Babbage was in essence applying industrial methods to the creation of the information that an industrial society increasingly required for further progress. But although his idea of industrializing mathematics was logical, Babbage was entering uncharted technological territory. From 1820 to 1822, Babbage constructed a small calculator that he called a difference engine. The calculator exploited a mathematical method for generating a table of numbers and their squares by repeated simple subtraction and addition. When the demonstration model successfully generated numbers up to about eight decimal places, Babbage undertook to build a larger scale version, which he called Difference Engine Number One. This machine would have around 25,000 gears and other moving parts and could handle numbers with up to 20 decimal places. The machine was even to have a printer that could generate the final tables directly, avoiding transcription errors.
By 1830, work was well under way, supported by both government grants and Babbage’s own funds. However, Babbage soon became bogged down with problems. Fundamentally, the parts for the Difference Engine required a tolerance and uniformity that went beyond anything found in the rough-hewn industry of the time, requiring new tools and production methods. At the same time, Babbage was a poorer manager than an inventor, and in 1833 labor disputes virtually halted the work. The big Difference Engine would never be finished.
By 1836, however, Babbage, undaunted, had developed a far bolder conception. He wrote in his notebook, “This day I had for the first time a general . . . conception of making an engine work out algebraic developments. . . . My notion is that the cards (Jacquards) of the calc. engine direct a series of operations and then recommence with the first, so it might be possible to cause the same cards to punch others equivalent to any number of repetitions.”
As Babbage worked out the details, he decided that the new machine (which he called the Analytical Engine) would be fed by two stacks of punched cards. One stack would contain instructions that specified the operation (such as addition or multiplication), while the other would contain the data numbers or variables. In other words, the instruction cards would program the machine to carry out the operations automatically using the data. The required arithmetic would be carried out in a series of gear-driven cal-culation units called the mill, while temporary results and variable values would be stored in a series of mechanical registers called the store. The final results could be either printed or punched onto a set of cards for future use. The Analytical Engine thus had many of the features of a modern computer: a central processor (the mill), a memory (the store), as well as input and output mechanisms. One feature it lacked, as revealed in Babbage’s journal entry, was the ability to store programs themselves in memory. That is why a repetition (or loop) could be carried out only by repeatedly punching the required cards.
The new machine would be a massive and expensive undertaking. Babbage’s own funds were far from sufficient, and the British government had become disillusioned by his failure to complete the Difference Engine. Babbage therefore began to use his contacts in the international mathematical community to try to raise support for the project. He was aided by L. F. Menebrea, an Italian mathematician, who wrote a series of articles about the Analytical Engine in France. He was further aided by ADA LOVELACE (the daughter of the poet George Gordon, Lord Byron). She not only translated the French articles into English, but greatly expanded them, including her own example programs and suggestions for applications for the device.
However, like the Difference Engine, the Analytical Engine was not to be. A contemporary wrote that Babbage was “frequently and almost notoriously incoherent when he spoke in public.” His impatience and “prickliness” also made a bad impression on some of the people he had to persuade to support the new machine. Funding was not found, and Babbage was only able to construct demonstration models of a few of its components. As he moved toward old age, Babbage continued to write incredibly detailed engineering drawings and notes for the Analytical Engine as well as plans for improved versions of the earlier Difference Engine. But he became reclusive and even more irritable. Babbage became notorious for his hatred of street musicians, as chronicled in his 1864 pamphlet Observations of Street Nuisances. Neighbors who supported the musicians often taunted Babbage, sometimes organizing bands to play deliberately mistuned instruments in front of his house.
After Babbage’s death in October 18, 1871, his remarkable computer ideas faded into obscurity, and he was remembered mainly for his contributions to economic and social statistics, another field that was emerging into importance by the mid-19th century. Babbage therefore had little direct influence on the resurgence of interest in automatic calculation and computing that would begin in the late 1930s (many of his notes were not unearthed until the 1970s). However, computer scientists today honor Charles Babbage as their spiritual father.