From the 17th century onwards people had made many attempts to devise a mechanical log which would automatically record the ships distance done. Edward Massey invented a mechanical log in 1802 with four blades which was used by the Admiralty from 1807-1815. When dragged behind the ship the log vins rotates and the revolutions were transformed in miles on the dials, to be read after the log was brought in. The design of Massey was further refined by Thomas Walker and Son, who took out a patent for the A1 Harpoon Log in 1861. Heath & Co., instrumentmakers in London from 1845-1910, made only a few harpoonlogs based on Walkers patent of 1861, also with stabilizer.

This A2 log without stabilizer came after the A1. Rotary slide twists to reveal three dials on porcelain face. The first registers the miles up to 100, the second registers the units up to 10 mile, the third registers quarters of a mile. The four rotor blades are stamped with anchor motif and initials T.W.
The production commenced in 1863 and ceased in 1919. Mainly used in steam powered high speed vessels such as used by the Royal Navy.
Details and design features suggest manufacture date around 1880.

The original chest of pine with cautions and the Walker sticker is also complete with signs of using and painted in romantic redbrown.

Catalog: NM.3-27
Date: ca. 1880
L: 50 cm (19.7 in)
Signed: T. WALKER’S Patent HARPOON SHIP LOG A.2. London.
Origin: England
Condition: perfect with signs of use