Charles Babbage'S Computer Engines
The Difference and Analytic Engines: precursors of modern computers. It took the wild mind of Charles Babbage to come up with it!
Mathematician and inventor Charles Babbage had already fallen out of favor with the British government and mathematical community before his death in 1871. He was a visionary, and like many visionaries, saw too far ahead of his time for his peers to fully comprehend or appreciate.
Babbage was born December 26, 1792, to a banker in Totnes, Devonshire, England. Babbage had many brothers and sisters, but most died before adulthood, and like them, he was sickly as a child. Even before his formal education began, he was a tinkerer. He loved to take mechanical things apart, and did little else with his toys besides dissect them.
Eventually Babbage was put in the care of a church school near Exeter, where the minister was told by his family to make sure that Babbage was healthy, rather than well-educated. Because of this concern, the minister didn't give Babbage enough work to keep him interested and occupied. Superstitious, despite a thorough Protestant upbringing, Babbage developed an obsession with the Devil. He asked his classmates to tell him every folk tales they knew about what forms the Devil appeared in.
Babbage didn't really believe in ghosts and spirits, but he decided to give them a fair chance and made a test of the tales his classmates had told him about the Devil. He went up to the school attic, cut himself and drew a circle on the floor and even recited the Lord's Prayer in reverse. It was obvious, though, that the Devil had no intention of making a pact with Charles Babbage -- none of his forms appeared, and Babbage was satisfied that all spirits and demons were figments of the imagination.
As he reached a healthy maturity, he went to a series of new schools, finally ending up at Forty Hill, where he was notorious for mischief combined with an odd desire to study. He was never a perfect scholar -- he carved his name in his desks, violated his curfew, and insulted the minister's sermons. But somehow he found time to wake up with a friend at three in the morning and study in the library until five thirty when they were scheduled to begin their regular day. Eventually his roommate, Frederick Marryat, a future novelist, managed to join the morning study group and brought bunches of friends along. Soon it degraded from studying to a wild party which was eventually broken up by the headmaster. Many years later, when he was a prosperous author and Babbage a famous mathematician, Marryat loved to tell people that he and Babbage had been known at Forty Hill as the two students who would never amount to anything.
Babbage's first invention came about one summer when he was at his father's country home. Swimming in the river, he realized that it would be easy to walk on water if he strapped huge books to his feet in such a way that when he lifted his foot up the book would close and when he set it down, the book would open, pushing or keeping him on top of the water's surface. The principle of the invention was correct, but the crude mechanics of it caused him to tilt heavily to one side and eventually fall into the water.
Shortly thereafter, Babbage's father acquired a tutor from Oxford to help finish his education to the point where he could be admitted to a college such as Cambridge. Babbage worked on grammar and reading the classics, but his passion was for mathematics. In his spare time he read such books as The Young Mathematician's Guide, Analytical Institutions (Madam Agnesi), many books of fluxions and Joseph Lagrange's Theorie des Fonctions, which described the work of another mathematician, Leibnitz, who used a "d" to represent what Newton's calculus used dots for. Babbage was impressed by the "d's" because they made reading the formulae much easier. The dots were small and could get blurred into the other symbols printed on the page, and were more easily forgotten by printers.
When he finally got to Cambridge at age nineteen, Babbage was frustrated by his teachers because they never answered his questions. He would listen to their lectures and then come up with new ideas based on what they had said. When he asked them about his ideas, they told him that he could rest assured he would not be tested on it. Even when he insisted that he wanted to know, the teachers refused to answer. Babbage soon concluded that none of the tutors or teachers at Cambridge knew as much about calculus as he did. His assumption was correct: the entire community of English mathematicians was very closed to change or new ideas coming from any corner, and calculus was rapidly changing.
Babbage's first service to the world as a mathematician was to throw some salt in the face of Cambridge. A controversy was going on at Cambridge about publishing an edition of the King James Bible with footnotes in it pointing out places where the translation was incorrect. The debate centered around challenging the letter of the Bible used by the Church of England. Babbage didn't care about the King James Bible, but he saw it as an excellent opportunity to parody the Cambridge mathematics department.
He wrote a flier about a fictional militant group of mathematicians who planned to translate new works about calculus that had not been written in English. The group would primarily focus on forcing the Cambridge mathematical community to accept Leibnitz's d's in the place of Newton's dots. Babbage showed the flier to a fellow student who showed it to a mathematician of some acclaim. The mathematician took it around to his friends and colleagues, and eventually one of them wondered why what started as a joke shouldn't become a reality.
Babbage and some other students formed the Analytical Society. The society met daily and wrote enough papers that they published a volume of transactions, mostly written by Babbage and John Herschel. Babbage remembered his original flier and entitled the transactions, The Principles of Pure d-ism in opposition to the Dot-age of the University. For obvious reasons, the Analytical Society was detested by the Cambridge mathematics department. Though they were a group of jokers, John Herschel, Charles Babbage and George Peacock also had a serious goal which Babbage summed up as: "Let us leave the world a wiser one than we found."
Babbage was also part of some sillier societies, including the Ghost Club, which investigated claims of the supernatural and, by far the most outlandish, the Extractors Club who made sure that every member of their group thrown in the madhouse was gotten out, legally, or illegally.
Meanwhile the Analytical Society busied itself by checking celestial tables used by sailors and astronomers for navigational and locational purposes respectively. Babbage noticed that the number of simple mathematical mistakes and printers' errors in the tables could have lost many lives at sea, and many opportunities to see celestial bodies for astronomers. Frustrated with the tables one evening while making corrections to them, Babbage got the idea that a machine could produce them, eliminating the simple human errors he found so frequently. This began his life's work on building adding machines.
Babbage started collecting calculating machines a few years later. He was searching for one that would not have or cause the problems he had seen in tables of numbers. It needed to be the sort of thing you could plug the numbers into, tell it the operation, and have it spit out the correct answer, whether or not the user understood the operation. It also needed to be "self acting" in that once an initial switch or lever was pulled it did all the work by itself. Aside from these criteria, he thought that a machine that printed out its answers would eliminate another place where human error was possible. He found no machine that met his standards, so he designed one.
Babbage's first calculating machine was the Difference Engine, which created tables of values by finding the common difference between terms in the sequence. The Difference Engine could print out a table of values for a number of terms in the sequence only limited by the number of digits the machine had available to work with. The idea was that astronomical tables could be printed out using such a machine, as well as simple lists of prices for a butcher's shop that charged by the pound.
The Difference Engine was wonderful for creating accurate tables of star positions at certain dates, for use by astronomers and sailors. The prototype of the machine was more accurate than human calculation, because it did not make stupid errors or miscopy its figures. The real model of the engine was never completed, much to the disappointment of the British government.
The Difference Engine was never completed because Babbage could never stick with a single blueprint for it. He had a habit of constantly thinking of ways to slightly improve it that involved new parts, ripping old parts out, and most notably, a great deal of money. Thousands of pounds of government funding were used rebuilding the same parts over and over as Babbage refined them. Never actually completed or used, the Difference Engine's main contribution to the world ended up being the ideas it inspired in Babbage's mind, which eventually lead to his next engine, and computer programming.
Babbage's real genius only manifested in his second attempt at creating an adding machine, the Analytical Engine. In three ways, the Analytical Engine led to modern computers. For this engine, Babbage borrowed a concept from the weaving industry -- punch cards. A Jacquard loom uses cards with patterns punched into them to tell the machinery what to weave. Babbage realized that mathematical functions could be placed on similar cards so that all a mathematician had to do was create the right card, and anybody could put it into the machine and set it to go.
Babbage devised two separate parts for the Analytical Engine, which were like a factory and a retailer. You told the retailer part of his device what you wanted to get in the end. Typing a simple command into a computer, such as "dir" in DOS is exactly this. You are telling the computer that you want a listing of everything in the specified directory. The computer then translates this into something its parts can understand; hence the retailer turns around and talks to the factory workers in a technical factory language. They complete the process, and give it back to the retailer, who must again translate it from their language to yours.
Before Babbage's intuition, mathematicians building adding machines had asked themselves the obvious question, "If we want this result, how can we get this result?" Babbage's roundabout approach to that question was the first part of the dream of computer programming. Without his concept of a translator, the modern computer program could not exist.
Late in the development of the Difference Engine, Babbage had realized that by connecting a few small gears, the engine could take the answer it had just found and run it through another set of manipulations. Babbage had discovered a sort of early virtual memory, and he built it into his plans for the Analytical Engine.
Unfortunately, the Analytical Engine was not heralded by British society as the most wonderful invention of the 19th century. It received almost no attention. After failing to complete the Difference Engine, Babbage fell out of favor with his mathematical peers. It wasn't until much later that his ideas were rediscovered, and combined with the findings of others (electric calculating machines) to create something very closely resembling a modern computer. But looking at Babbage's punch cards, they very closely resemble a modern program in Basic.
All of Babbage's work went toward making the daunting simple. His adding machines were meant to carry out tedious work perfectly, sparing human effort and mistakes. Babbage was devoted to making the world an easier one, to opening the doors of understanding and applications of mathematics. Eventually, his ideas went to this end, helping calculators and computers -- which are considered by many the finest tool of the modern era -- get their start.
He died lonely and cynical, but his ideas have met a bright future, bouncing from one field of study to another, from one corner of the world to the next.