THE ADVENTURE OF THE ENGINEER'S THUMB by Sir Arthur Conan Doyle

An engineer, by the name of Victor Hatherley, has had his thumb chopped off in a murderous attack. Hatherley had been employed by a shadowy German figure to repair a hydraulic press, and when the engineer had found out too much its operation.

First published in the Strand Magazine, Mar. 1892, with 8 illustrations by Sidney Paget.