4 ms·

The impression I have gotten from articles which look at the Analytical Engine more critically is that Babbage had the habit of trying to upsell his investors i

The impression I have gotten from articles which look at the Analytical Engine more critically is that Babbage had the habit of trying to upsell his investors into a more complex, more risky, more academically interesting device without completing the last one. The Difference Engine actually was completed eventually and ordered by the British government, in a more pragmatic form: https://en.wikipedia.org/wiki/Difference_engine#Scheutzian_calculation_engine https://en.wikipedia.org/wiki/Difference_engine#Scheutzian_c... That said I do agree with what was said in the thread. There was a lot of accidental complexity in early numeric computers. I feel a true programmable computer could not have come about without the development and refinement of symbolic logic that took place in the 20th century.

grahamm 5y ago
"Babbage had the habit of trying to upsell his investors into a more complex, more risky, more academically interesting device without completing the last one." Omg the oracle business model was born....
- jacquesm 5y ago
  Don't forget about Moller.
svat 5y ago
His "investors" being in this case the government, and Babbage does not seem to have understood politicians or the constraints that a government operates under. You can see the timeline in https://www.gutenberg.org/files/57532/57532-h/57532-h.htm#p068 https://www.gutenberg.org/files/57532/57532-h/57532-h.htm#p0... Chapter VI (with the caveat that, though this chapter is written by a third person, this being Chapter VI of Babbage's autobiography/memoirs, clearly it must have been sufficiently sympathetic to him that Babbage included it in his book). But the short version is that, far from it being a "habit", he seems to have done what you said only once, in 1834, when he started to have ideas for an Analytical Engine, which would have completely superseded the Difference Engine that he had already been building for the government for 11 years at that point (initial estimate had been 2–3 years). The relationship between the government and him were already strained, but he doesn't seem to have understood that and got further entangled, instead of extricating himself. He asked the government what their plan was (in light of this development), and it took them until 1842 to make a decision (just give up on it entirely). ---- Slightly longer version of the timeline that I started reconstructing, before abandoning it: • In around 1812 or 1813, he had the germ of the idea "that all these Tables (pointing to the logarithms) might be calculated by machinery". Between 1820 and 1822, he made his own Difference Engine (two orders of difference, 6 digits). • In 1823, Babbage started making "a much larger and more perfect engine" for the government, and this is where the trouble starts. The plan was for this machine to have "six orders of differences, each consisting of about twenty places of figures". • Unfortunately, the conversation was informal and the details of the arrangement were not written down(!), which led to misunderstandings over the years as Babbage came back and asked for more money: work ceased in May 1829, resumed in February 1830, etc. Then in September 1834 that "Analytical Engine" event (idea) happened. • Just before this, in July 1834, Lardner in The Edinburgh Review wrote "a very elaborate description of this portion of the machine" (took me some searching but I found it! here: https://archive.org/details/edinburghreviewo59macauoft/page/262/mode/2up https://archive.org/details/edinburghreviewo59macauoft/page/... ), and this inspired Scheutz in Sweden to build a machine as described. As Wikipedia describes, the Swedish machine went up to the third order (not sixth), and had 5-digit numbers (not 20). This was completed in 1843. • In 1853, a larger (fourth-order, 15 digits) Swedish machine was built, exhibited in 1855 and sold in 1856, delivered in 1857. The British government commissioned a copy of it, which was built in 1859. (Note that this was still smaller than the design which Babbage was close to completing in 1834 or even 1842… oh well.) • Note the ending of the 1834 article (https://archive.org/details/edinburghreviewo59macauoft/page/326/mode/2up https://archive.org/details/edinburghreviewo59macauoft/page/...): already in 1834 people were wondering why on earth Babbage and the government don't bring this matter to a quick conclusion.
- shadowofneptune 5y ago
  Ok, I concede that, it was exagerrated in what I was reading. What do you think about the other point? Was a computer as we know it today practical to design before the discovery that arithmetic and other principles of math could be worked out using logic?
  - svat 5y ago
    I'm not an expert (my only qualification is that I read a part of Babbage's book; others must know a lot more), but see http://tomforsyth1000.github.io/blog.wiki.html#%5B%5BBabbage%20was%20a%20true%20genius%5D%5D http://tomforsyth1000.github.io/blog.wiki.html#%5B%5BBabbage... and (linked from it) https://www.fourmilab.ch/babbage/cards.html https://www.fourmilab.ch/babbage/cards.html — it looks like he did have a reasonable design of a computer in fact. (Except for the too-many-digits-of-precision thing, that the OP tweet thread is about.) He seems to have well understood how not just arithmetic but a lot more could be done mechanically.

grahamm 5y ago

"Babbage had the habit of trying to upsell his investors into a more complex, more risky, more academically interesting device without completing the last one." Omg the oracle business model was born....

jacquesm 5y ago
Don't forget about Moller.

svat 5y ago

His "investors" being in this case the government, and Babbage does not seem to have understood politicians or the constraints that a government operates under. You can see the timeline in https://www.gutenberg.org/files/57532/57532-h/57532-h.htm#p068 https://www.gutenberg.org/files/57532/57532-h/57532-h.htm#p0... Chapter VI (with the caveat that, though this chapter is written by a third person, this being Chapter VI of Babbage's autobiography/memoirs, clearly it must have been sufficiently sympathetic to him that Babbage included it in his book). But the short version is that, far from it being a "habit", he seems to have done what you said only once, in 1834, when he started to have ideas for an Analytical Engine, which would have completely superseded the Difference Engine that he had already been building for the government for 11 years at that point (initial estimate had been 2–3 years). The relationship between the government and him were already strained, but he doesn't seem to have understood that and got further entangled, instead of extricating himself. He asked the government what their plan was (in light of this development), and it took them until 1842 to make a decision (just give up on it entirely). ---- Slightly longer version of the timeline that I started reconstructing, before abandoning it: • In around 1812 or 1813, he had the germ of the idea "that all these Tables (pointing to the logarithms) might be calculated by machinery". Between 1820 and 1822, he made his own Difference Engine (two orders of difference, 6 digits). • In 1823, Babbage started making "a much larger and more perfect engine" for the government, and this is where the trouble starts. The plan was for this machine to have "six orders of differences, each consisting of about twenty places of figures". • Unfortunately, the conversation was informal and the details of the arrangement were not written down(!), which led to misunderstandings over the years as Babbage came back and asked for more money: work ceased in May 1829, resumed in February 1830, etc. Then in September 1834 that "Analytical Engine" event (idea) happened. • Just before this, in July 1834, Lardner in The Edinburgh Review wrote "a very elaborate description of this portion of the machine" (took me some searching but I found it! here: https://archive.org/details/edinburghreviewo59macauoft/page/262/mode/2up https://archive.org/details/edinburghreviewo59macauoft/page/... ), and this inspired Scheutz in Sweden to build a machine as described. As Wikipedia describes, the Swedish machine went up to the third order (not sixth), and had 5-digit numbers (not 20). This was completed in 1843. • In 1853, a larger (fourth-order, 15 digits) Swedish machine was built, exhibited in 1855 and sold in 1856, delivered in 1857. The British government commissioned a copy of it, which was built in 1859. (Note that this was still smaller than the design which Babbage was close to completing in 1834 or even 1842… oh well.) • Note the ending of the 1834 article (https://archive.org/details/edinburghreviewo59macauoft/page/326/mode/2up https://archive.org/details/edinburghreviewo59macauoft/page/...): already in 1834 people were wondering why on earth Babbage and the government don't bring this matter to a quick conclusion.

shadowofneptune 5y ago
Ok, I concede that, it was exagerrated in what I was reading. What do you think about the other point? Was a computer as we know it today practical to design before the discovery that arithmetic and other principles of math could be worked out using logic?
- svat 5y ago
  I'm not an expert (my only qualification is that I read a part of Babbage's book; others must know a lot more), but see http://tomforsyth1000.github.io/blog.wiki.html#%5B%5BBabbage%20was%20a%20true%20genius%5D%5D http://tomforsyth1000.github.io/blog.wiki.html#%5B%5BBabbage... and (linked from it) https://www.fourmilab.ch/babbage/cards.html https://www.fourmilab.ch/babbage/cards.html — it looks like he did have a reasonable design of a computer in fact. (Except for the too-many-digits-of-precision thing, that the OP tweet thread is about.) He seems to have well understood how not just arithmetic but a lot more could be done mechanically.