"On two occasions I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to a

"On two occasions I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question." -- Charles Babbage The article says that his engine "would have done it far better than the existing mechanisms (a room full of people adding stuff manually)." I seem to recall, though, that a bunch of people adding stuff up wasn't the only approach. I think a lot of mechanical (i.e. analogue) devices were used to perform computation (e.g. tide prediction machine https://www.youtube.com/watch?v=uFhjGlriDYE https://www.youtube.com/watch?v=uFhjGlriDYE). Like a lot of tech, there was a cross-over period in which machines were quite competitive with digital devices, until the new tech eventually held sway. Here's on on a differential analyser: https://www.youtube.com/watch?v=LqTL2JBETzE https://www.youtube.com/watch?v=LqTL2JBETzE. You can basically solve differential equations using a series of pulleys and gears.