The Difference Engine: Charles Babbage and the Quest to Build the First Computer by Doron Swade

This is one of those hero-destroying books.

Not Charles Babbage, but rather Lady Ada Lovelace, daughter of Lord Byron, who is often heralded as the First Computer Programmer and the person who basically invented the concept of programming long before there was a machine to program. But, like most deified historical figures, it’s not quite so. Probably. She may not even be rightfully called “The Enchantress of Number”. (Charles Babbage is said to have called her that in a letter, but close scrutiny shows that he may very well have just been referring to his love of numbers themselves.)

What happened, according to the author (who I find credible), is that Charles Babbage got frustrated with calculating and checking navigational tables by hand. Back in the day (and we’re talking 1800’s), a computer was a human who did calculations, usually women. Mr. Babbage may or may not have cried “I wish to God these calculations had been executed by steam.” Early on, Charles wasn’t sure whether he or his friend John Herschel had said that, but later on (apparently recognizing a great Eureka story when he heard it) definitively claimed he had.

So, he designed Difference Engine No. 1, a mechanical apparatus for doing basic calculations. The English government financed it’s construction, but it was never finished. Everything takes longer and costs more than you expect in engineering. Also, during this work, Charles Babbage envisioned a grander machine, a more general purpose machine, The Analytical Engine. This machine bears some eerily similar structure to our modern day computers, albeit realized in gears instead of microchips. The design for this machine was never finished, and of course never built.

But it is at this point that our heroine, Lady Ada enters the picture. She met Charles, and was taken by his idea. One of the few women trained in mathematics, Ada was about as arrogant about her brilliance as anyone can hope to be. She corresponded regularly with Charles about the machine, throwing back and forth ideas about it’s potential.

Someone in Italy published a review of Charles’ Analytical Engine idea, and Lady Ada undertook to expand and publish the work in England. The piece was called Sketch of the Analytical Engine, and in it we find the basis of Lady Ada lore. This is the first time the concept of a “program” (though it was not referred to as such in that time period) was recorded in an official paper, but such ideas had been expounded upon by Babbage much earlier in the development of the Engine.

There is the possibility that she may have further developed concepts of symbolic manipulation beyond what Babbage originally conceived. Where Babbage mentions early on the idea of doing calculations without numbers solely by algebraic representation, he stayed firmly in the realm of mathematic applications in his writings and musings.

In Sketch, Ada writes:

Suppose, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptions, the Engine might compose elaborate and scientific pieces of music of any degree of complexity or extent.

Bold thinking about a bunch of gears in the mid 1800s.

So, perhaps there is a bit of heroinism there. She certainly stepped out of the mold set for her in society, and dared dream of creative machines.

Plus, she was cute.

The Lady Ada story is a single chapter in this book. The first part is the story of Babbage and his machine designs. The second part tells the story of the author’s quest to build Difference Engine No. 2, an improved version of Difference Engine No. 1 using ideas Babbage had while designing the Analytical Engine. Some guys from the Science Museum in England built it and had it working by the bicentennial of Babbage’s birth, using tolerances and materials that had been available in Babbage’s time. Historians had theorized that Babbage had not been able to complete his work because the state of the art at the time could not handle the precision needed for the machine. They proved that wrong.

It was just that Babbage had too many other obstacles, not the least of which was his own tendancy to go off on tangents.

I can relate to that. I’m going back to work, now.