查尔斯·巴贝奇

His parents ordered that his "brain was not to be taxed too much" and Babbage felt that "this great idleness may have led to some of my childish reasonings." He was sent to King Edward VI Grammar School in Totnes, South Devon, a thriving comprehensive school still extant today, but his health forced him back to private tutors for a time. He then joined a 30-student academy under Reverend Stephen Freeman. The academy had a well-stocked library that prompted Babbage's love of mathematics. He studied with two more private tutors after leaving the academy. Of the first, a clergyman near Cambridge, Babbage said, "I fear I did not derive from it all the advantages that I might have done." The second was an Oxford tutor from whom Babbage learned enough of the Classics to be accepted to Cambridge.

Babbage arrived at Trinity College, Cambridge in October 1810. He had read extensively in Leibniz, Lagrange, Simpson, and Lacroix and was seriously disappointed in the mathematical instruction available at Cambridge. In response, he, John Herschel, George Peacock, and several other friends formed the Analytical Society.

In 1812 Babbage transferred to Peterhouse, Cambridge. He was the top mathematician at Peterhouse, but failed to graduate with honours. He instead received an honorary degree without examination in 1814.

In recognition of the high error rate in the calculation of mathematical tables, Babbage sought to find a method by which they could be calculated mechanically, removing human sources of error. This idea may have come to him as early as 1812年. Three different factors seem to have influenced him: a dislike of untidiness; his experience working on logarithmic tables; and existing work on calculating machines carried out by Wilhelm Schickard, Blaise Pascal, and Gottfried Leibniz. He first discussed the principles of a calculating engine in a letter to Sir Humphrey Davy in 1822年.

Part of Babbage's difference engine, assembled after his death by Babbage's son, using parts found in his laboratory.

Babbage presented a model of what he called a difference engine to the Royal Astronomical Society on June 14, 1822年 and in a paper entitled "Note on the application of machinery to the computation of astronomical and mathematical tables."[1] It calculated polynomials using a numerical method called the differences method. The Society approved the idea, prompting the government to grant £1500 for its construction in 1823年.

Babbage converted one of the rooms in his home to a workshop and hired Joseph Clement to oversee construction of the engine. Every part had to be formed by hand using custom machine tools, many of which Babbage himself designed. He took extensive tours of industry to better understand manufacturing processes. Based on these trips and his experience with the difference engine, Babbage published On the Economy of Machinery and Manufacture[2] in 1832年. It was the first publication on what we would now call operations research.

The death of Georgiana, Babbage's father, and an infant son interrupted construction in 1827. Work had already taxed Babbage heavily and he was on the edge of a breakdown. John Herschel and several other friends convinced Babbage to take a trip to Europe to recuperate. He passed through the Netherlands, Belgium, 德國，和義大利 visiting universities and manufacturing facilities.

In Italy he learned he had been named the Lucasian Professor of Mathematics. He initially wanted to turn down the position but several friends convinced him to accept. He moved to 1 Dorset Street upon returning to England in 1828年.

The difference engine project had come under fire during Babbage's absence. Rumours had spread that Babbage had wasted the government's money; that the machine did not work; and that it had no practical value if it did. John Herschel and the Royal Society publicly defended the engine. The government continued its support, advancing £1500 on April 29, 1829年, £3000 on December 3, and £3000 on February 24, 1830年. Work continued, but Babbage would have continual difficulty getting money from the treasury.

Babbage's problems with the treasury coincided with numerous disagreements with Clement. Babbage had built a two-story, 50 foot long workshop behind his house. It had a glass roof for lighting, and a fireproof, dust-free room to contain the machine. Clement refused to move his operations to the new workshop and demanded more money for the difficulty of travelling across town to oversee construction. In response, Babbage suggested that Clement draw his pay directly from the treasury. Before then, Babbage would get money from the government that he would use to pay Clement. He often had to pay Clement out of his own pocket when the bureaucracy lagged behind Clement's pay schedule. Clement refused the request and stopped working.

Clement further refused to turn over the drawings and tools used to build the difference engine. After an investment of £23000, including £6000 of Babbage's own money, work on the unfinished machine ceased in 1834年. Charles wrote, "The drawings and parts of the Engine are at length in a place of safety—I am almost worn out with disgust and annoyance at the whole affair." In 1842年 the government officially abandoned the project.

While he was separated from the difference engine, Babbage began to think about an improved calculating engine. Between 1833年 and 1842年 he tried to build a machine that would be programmable to do any kind of calculation, not just ones relating to polynomial equations. The first breakthrough came when he redirected the machine's output to the input for further equations. He described this as the machine "eating its own tail". It did not take much longer for him to define the main points of his analytical engine.

The mature analytical engine used punched cards adapted from the Jacquard loom to specify input and the calculations to perform. The engine consisted of two parts: the mill and the store. The mill, analogous to a modern computer's CPU, executed the operations on values retrieved from the store, which we would consider memory. It was the world's first general-purpose computer.

A design for this emerged by 1835年. The scale of the work was truly incredible. Babbage and a handful of assistants created 500 large design drawings, 1000 sheets of mechanical notation, and 7000 sheets of scribbles. The completed mill would measure 15 feet tall and 6 feet in diameter. The 100 digit store would stretch to 25 feet long. Babbage constructed only small test parts for his new engine; a full engine was never completed. In 1842年, following repeated failures to obtain funding from the First Lord of the Treasury, Babbage approached Sir Robert Peel for funding. Peel refused, and offered Babbage a knighthood instead. Babbage refused. He would continue modifying and improving the design for many years to come.

In October 1842年, Federico Luigi, Conte Menabrea, an Italian general and mathematician, published a paper on the analytical engine. Augusta Ada King, Countess of Lovelace, a longtime friend of Babbage, translated the paper into English. Charles suggested that she add notes to accompany the paper. In a series of letters between 1842年 and 1843年, the pair collaborated on seven notes, the combined length of which was three times longer than the actual paper. In one note Ada prepared a table of execution for a program that Babbage wrote to calculate the Bernoulli numbers. In another, she wrote about a generalized algebra engine that could perform operations on symbols as well as numbers. Lovelace was perhaps the first to grasp the more general goals of Babbage’s machine, and some consider her the world's first computer programmer. She began work on a book describing the analytical engine in more detail, but it was never finished. Well over a century later, an early programming language, Ada, was named in her honor.