English mathematician Charles babbage had worked out the basic design of a mechanical computer, by the 1840’s. He actually designed a prototype, and based upon this, got a grant from the British Admiralty to build a full-sized machine.
He failed, for reasons I am not clear about.
Was it that the machine tools of his era could not make gear wheels of sufficient accuracy?
Or was such a complex machine (with thousands of moving parts) impossible to operate reliability (with 19th century technology)?
In any case, had Babbage been successful, would his mechanical computer be nothing more than a limited use curiosity? How was this machine to be programmed?
The Science Museum in London built a working model based on the original plans. Its a thing of beauty to behold in action. There’s a book about the project called “The Difference Engine:Charles Babbage and the Quest to Build the First Computer” which explains how it works and some of the problems they encountered building it.
IIRC, they concluded that the Difference Engine could be built, using the technology of the time, but Babbage probably just ran out of money.
Old arguments, the testing of which was the whole motivation for the Science Museum’s (first) building of an actual Babbage Difference Engine. Pretty much nobody now thinks that there were any significant technological barriers to Babbage and his craftsmen building those designs. (I’m less convinced by the Analytical Engine designs being possible, but even that’s borderline.) His personality and project management skills are another matter.
It’s also usually overlooked that others did build and sell practical difference engines. But there wasn’t really a market for them. I doubt a full Babbage version would have found much more employment.
A second identical Engine completed in March 2008 is on display at the Computer History Museum in Mountain View, California.
Did these machines follow Babbage’s plan exactly? I assume there would be small problems that he could have fixed himself, but would they have worked without incorporating principles unknown to Babbage?
It’s worth noting that the Difference Engine was essentially just a kind of calculator (it could evaluate polynomials described in terms of their initial derivatives); it was only the Analytical Engine that acted as a general-purpose computer. I assume, because of the way you word this, that it’s really the Analytical Engine you are interested in rather than the Difference Engine, though Babbage himself built neither in the end.
It’s my understanding that Babbage had a difficult personality, and many potential investors were put off by it.
And I can testify it is quite awesome. I’m not sure when it is leaving, but if it is still around you should drop in. Admission is free.
(I am so volunteering there when I retire. They’ve got lots of computers I used to play with in the good old days, including a PDP-1. )
Ohhhh we used to DREAM of havin’ 18 bit words. Woulda’ been a palace to us.
What kind of psychotropic drugs was that guy on?
The machine is a freaking piece of complex beauty, and that’s only from a video.
love the video.
note well the double helix! spooky.
Here is a short Youtube of the Mountain View engine in action, complete with sound. I think it needs a little grease.
The normal manufacturing processes of engine makers would not have been good enough to produce a machine that could actually be operated by available power sources, but jewelry and clockwork tolerances would have. That complication introduces a very large increase in the cost of building the thing. There are some tales that a second machine, a printer, if you will were also made, and pair of devices then could have actually created finished five digit trigonometric tables, and log tables. Military applications would have made that machine worth the money. (Doing that by hand was not possible, since errors were inevitable, and proofread errors likewise inevitable.)
Tris
Yuppers! The difference machine is actually capable of laying out type which automatically is pressed into a plaster mold which can be used to cast the actual printing block. Unbelievable!
I understand that Babbage had a very bad case of perfectionism going on. Meaning that he would design some components or parts of his device, but, halfway through building them, he would suddenly think of a way to make it “even better”, stop everything, tear down what he had built until then, and re-design everything from the beginning.
Investors ended up tiring of him and of not having any results coming from him. I guess that if he had been less of a perfectionist he might have achieved something more tangible.
From this site:
As closely as possible, given the difficulties of interpreting multiple drafts of the surviving drawings and the fact that the design evolved over the years. There was at least one instance where Babbage’s mechanism was unambiguous on the paper, but impossible - once in motion it would have involved one bit of metal miraculous passing through another. The build team had to come up with a work-around in the spirit of the rest of the design.
Part of reason the build project came about was the realisation that a near complete set of plans did exist for Engine No. 2, more so than for the more cumbersome and abandoned No. 1. Similarly, I’m not sure that any future attempt to build the Analytical Engine would, in contrast, be anything more than a curiosity. While the principles are clear and his detailed designs exist for parts of the whole, there was never anything as complete on paper as for No. 2. We can understand how it would have worked and see that Babbage had made the great conceptual breakthrough, but there are fairly large blank areas in terms of the detailed gearing.
Personally, I think it’s now pretty obvious that had he concentrated on building No. 2 and not pissed various people off, they could have done it. The decision to abandon the first design was sensible and the work already done on it wouldn’t, in hindsight, have seemed wasteful. As JoseB pointed out, he was a designer who was always more interested in yet more improvements to the design, rather than realising that you take that process so far, then freeze the design and actually build the damn thing. IIRC, even the relatively complete and coherent set of plans for No. 2, which made the 20th century version possible, was a task forced upon him.
While he did run out of funds, it’s difficult to argue this was the fundamental limitation. The famous usual comparison is that the government had awarded him the equivalent of the cost of a new battleship and got nothing in return. Had he focussed on delivering something, there would have been enough money.
While his personality was the main obstacle, I should note that there is the natural bias in the popular literature towards the (true) stories of him as the cantankerous semi-reclusive weirdo. He was always eccentric, but in his younger days had been quite the social gadfly and his salon a hit amongst London society. The vision of him as the locked away bitter crank railing against accordianists misses just how important he earlier was as a reforming figure in the British science of the time. Even if he’d never so much thought of a cog. Similarly, Stephen Fry’s old piss-take of him on QI rather missed the point that Babbage himself had probably been making exactly the joke Fry was.
Even when it’s digressing into one of his odd obsessions, the Autobiography is a perfectly charming and entertaining piece of literature.
And he did have a point about accordianists.