Analytical machines: Ludgate, Torres y Quevedo, and Bush

[EdS]

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.)

Percy Ludgate

Leonardo Torres Quevedo

Vannevar Bush

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And there is just an interesting article from the HNF blog. A small business thriller in which Ludgate and Zuse (and maybe IBM) act. (Unfortunately only in German, but with many references.)

Percy Ludgate und Konrad Zuse | HNF Blog