This electric log recorder has a mahogany case that is fixed into an outer glazed mahogany case. The dial is hand-painted, with a scale from 0 to 10 miles and an inset dial from 0 to 100. There are brass electrical connections on the side of the case. In use, the recorder would have been connected to a rotor that was towed behind the ship. As the rotor turned, its revolutions would be counted and converted into distance travelled on the recorder dial, from which the ship’s speed could also be calculated.

C.E. Kelway patented the electric log in 1876 (no. 1455). It was based on an adapted speed log produced by the Massey firm, but had the advantage that the recorder was on board, rather than being part of the rotor.