Analytical machines: Ludgate, Torres y Quevedo, and Bush

We’ve all heard of Babbage. But there were three other notable inventors or builders of analytical machines - machines capable of general computation. Here’s Brian Randell in 1980:
From Analytical Engine to Electronic Digital Computer: The Contributions of Ludgate, Torres, and Bush

Here’s a presentation on Ludgate and here’s a short document and a long one on his machine - it’s notable for being mechanical, multiplying using mixed-base logarithms, and performing division using a lookup table and multiplications. In 1909. (Another and short document here with diagrams.) (From this trove.)

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