The 19th Century “Difference Engine” is hard to describe. One is displayed at the Smithsonian’s National Museum of American History in Washington D.C.. Though it rarely draws crowds, never doubt that the Difference Engine was the first step the toward the high-powered, artificial intelligence (AI), we have today. The man who invented it, 200 years ago, was English mathematician Charles Babbage, at a time when they were still reliant on coal-fired steam power.
Babbage’s Difference Engine is a its simplest a hand-cranked mechanical computer. It prepares numerical tables using a mathematical technique known as difference. Early mathematicians had to calculate complicated tables by hand. Charles Babbage conceived of the earliest general-purpose computer. Though sadly never fully completed in his lifetime, a fragment built by his son, Henry, clearly demonstrates Babbage’s genius.
Babbage’s Difference Engines were the first successful automatic calculators, a fine example of precision Victorian engineering. The inventor also envisioned a mechanical device that would go beyond calculation and actually store the data it produced. What he foresaw was the modern computer, which is why Charles Babbage is fondly known as “The Father of Computing.”
Who was this amazing inventor and what exactly was a Difference Engine?
Charles Babbage was born in 1791, the son of a wealthy London banker. As a youth, Babbage taught himself algebra and mathematics. When he enrolled in Trinity College at Cambridge in 1811, he found himself far more advanced than his instructors. There, he befriended John Herschel and George Peacock. Together they formed ‘The Analytical Society’ for promoting and reforming mathematics.
The “Analyticals” gathered to discuss how science could best support the Industrial Revolution with better tools and techniques. Clearly a genius, Charles was also a charming young fellow, filled with a youthful determination. Babbage’s life was typical of a Victorian gentleman-scientist. His inherited wealth which allowed him to explore his boundless interests in mathematics and engineering.
Babbage was elected a fellow of the Royal Society in 1816, just two years out of Cambridge, and became Lucasian Professor of Mathematics in 1828, a position held by Isaac Newton and, much later, Stephen Hawking. He also attempted to reform the scientific organizations of the period, while calling on government and investors to give more money and prestige to scientific endeavor.
Babbage was driven by the urge to improve the quality of 19th-century life. He endlessly sought ways to take the drudgery out of factory work. His metering devices could automatically do the mindless counting of repeated actions in a mill. He invented a time clock for punching in and out factory workers. He even designed a device to record the direction of earthquake shocks!
Charles Babbage described his Difference Engine as an idea born of frustration.
During the summer of 1821, Babbage and John Herschel were in England editing astronomical tables used for navigation. It was a tedious task, and they were frustrated by all the errors they found. An exasperated, Babbage sat back and exclaimed, “I wish to God these calculations had been executed by steam!” Steam power was changing every facet of everyday life, why not this?
Tables of astronomical data were key to aiding navigation at sea. But because such tables were calculated by humans, they suffered from errors in both calculation and transcription. This was when Babbage became interested in calculating machinery, a passion that would consume the rest of his life. He left Cambridge, obsessed with the idea of using machines to speed up time-consuming mathematical calculations.
Babbage set to work on his Difference Engine, a machine that would use a complex, clockwork-type mechanism of gears to solve polynomial equations. He soon had a small working model in 1822 and presented a paper to the Royal Astronomical Society. He ended with much optimism: “I feel great confidence in the complete success of the plans I have proposed for a full-scale Difference Engine.”
He convinced the British government to fund his plan. The government saw the value in a machine that could calculate the many numerical tables used for navigation, finance, and engineering; thereby reducing human error and labor. His invention would prove far more difficult to build however.
Babbage based his machine on the mathematical method of finite differences, which was easier to implement using dozens of gear wheels than one based on multiplication. Although Babbage had once dreamed of a machine powered by steam, his actual design called for a human to turn a crank.
As building continued, parts ran smoothly enough to provided demonstrations to keep attention and funds flowing. Babbage often requested support from acquaintances in high society and was a splendid host. The Duke of Wellington came to call, even Charles Dickens. John Herschel used a seafaring comparison to explain its value: “An undetected error in a navigational table is like a sunken rock at sea, upon which it is impossible to say what wrecks may have taken place.“
Then there was Augusta Ada Byron, daughter of the poet, Lord Byron. She was both brilliant and beautiful. The machine impressed a teenage Ada Byron, whose sharp mind understood the implications of the machine. As a woman, Ada was not allowed to attend university, but her father supported her academic interests.
Ada was skilled at mathematics and one of the few who could understand and explain Babbage’s inventions. She devoted years to helping Babbage, writing explanations of his achievements, admiring his genius with platonic devotion. In 1835, Ada married William King, the first Earl of Lovelace and became Countess of Lovelace.
Babbage’s Difference Engine No. 1 was divided into two main parts: the calculator and the printer.
As the calculator cranked out the results, the printing mechanism both printed a table, while simultaneously making a wax mold to make printing plates. Engine No. 1 contained more than 25,000 different metal parts, so Babbage needed a skilled craftsman. Joseph Clement was an award-winning machinist whose work was highly valued for its precision.
Babbage and Clement were both brilliant, but too often locked horns. Clement demanded to be paid his worth. Babbage, concerned about costs, often checked Clement’s work, which eroded their relationship. In 1832, the two managed to produce a portion of the machine one-seventh the size of the complete engine. Babbage gave demonstrations of the working model across London.
Despite the successful scientific chatter, trouble was brewing for Babbage. Cost overruns, political opposition, and Babbage and Clement’s clashing personalities, were causing long delays. Eventually, the relationship between Babbage and Clement reached a boiling point. After yet another fight over costs, Clement through up his hands and quit.
The government was more interested in reliable tables than the machine that produced it. Though a demo model was constructed, funding was put on hold in 1832. Prime Minister Robert Peel had never liked Babbage personally and had been a skeptic of the Engine itself. In1843, Parliament voted to withdraw support. By then, the government had spent £17,500 (about US $3 million today), ten times the estimate, and waited 20 years, and still didn’t have a full working machine.
A decade later, two Swedish printers, Georg Scheutz and his son, Edvard, built a difference machine in 1853. The Scheutzes followed the design concepts of Babbage. Ironically, the British government purchased that one, which they demonstrated at the World’s Fair in 1855. This machine printed tables with unprecedented accuracy. Babbage endorsed the Scheutz’s work as he was now preoccupied with an even bigger idea.
After Difference Engine No. 1, he conceived of an even better machine that could perform not just one mathematical task but any kind of calculation. This Difference Engine No. 2 was to be his Analytical Engine, intended as a general manipulator, and had the characteristics of today’s modern computers.
Part of the reason for the failure of Engine No. 1 was Babbage’s growing preoccupation with No. 2.
His new Analytical Engine would be even more revolutionary, yet simpler in design. This new machine would be a general-purpose computer. Inspired by the punched cards used to set up industrial looms, Babbages’ Analytical Engine would store numbers and results, while a separate ‘mill’ would process them arithmetically, basically the forerunner to the electronic computer!
Ada Lovelace championed Charles Babbage’s new work by writing the first computer algorithm for his unbuilt Engine. As Ada described it: “We may say that the Analytical Engine weaves algebraic patterns just as the loom weaves flowers and leaves into cloth.” His punch card system was revolutionary as a punch cards were the key to the earliest electronic computers of the 1960s.
For her written descriptions of how the Engine could calculate, Ada King, Countess of Lovelace, has been dubbed the first computer programmer. Unfortunately, as was the Victorian rage at the time, Ada also became an opium addict. She died of cancer after a long battle, leaving Babbage mourning his beloved ‘interpretress.’ In the interim, Babbage had also lost his father, wife Georgiana, and four of their eight children.
Although Lovelace’s notes were hailed by leading scientists, they did not win Babbage any additional funding. Babbage learned much from designing Engine 1. No. 2 would not only calculate polynomials, but require only one third of parts. Engine No. 2 required only 8,000 parts and had a much more elegant and efficient design. It would weigh about 5 tons and measure 11 feet long and 7 feet high. He worked for another two years on the machine.
Though he devoted most of his time and fortune towards his new Analytical Engine, after 1856 he never succeeded in completing any of his designs. Despite his many achievements, the failure to construct his machines, and in particular the failure of his government to support his work, required him to use his own fortune. This left Babbage a disappointed and embittered man. He stopped work on the Analytical Engine in 1856.
Babbage died at his home in London in 1871, at the age of 79.
After his death, Babbage’s son, Henry, continued to work on his father’s inventions, inheriting the original components. Though Babbage’s work was continued, the Analytical Engine was never successfully completed. Henry produced working partial fragments, demonstrating the feasibility of his father’s design.
After his death, Babbage’s ideas passed into obscurity for decades. Over the course of the 20th century, though, his genius became clear. One of Henry’s ‘fragments’ went to Cambridge where it inspired Alan Turing, who developed the Colossus computer, used to decipher the Nazi ENIGMA coding device. Another fragment ended up at Harvard, inspiring Howard Aiken, who developed the IBM Mark 1 computer used by the U.S. in The Manhattan Project.
In 1985, a team at the London Science Museum set out to build a streamlined Difference Engine No. 2. The team created new designs adapted to modern manufacturing. Despite leaving behind detailed drawings, Babbage left few notes or explanations of how the pieces worked together. It took them 17 years and the 8,000 piece finished product went on display in 2002.
Babbage’s legacy is clear, whether leading to early computers like the ENIAC, Atlas, IBM 360, and Cray-1 – leading then to the 1980’s PC revolution, with the likes of HP, TI, Apple, and Commodore. This then lead to the 2000’s handheld revolution with the Palm Pilot, Blackberry, and iPhone. Then came the supercomputers, first developed by universities and the military, then by Microsoft, Google, and Meta (Facebook).
Now (for better or worse), in a rush to compete, they each have Artificial Intelligence (AI) capabilities, available to the general public. All this, because of Charles Babbage’s unrelenting genius and his Victorian Difference Engines.
