Walker's Harpoon Ship Log.

Brass tube (53 cm) with fastening eye and rope, an inset log on an enamel plate marked with 10's of miles up to 100, miles up to 10, and fractions of a mile divided by quarters, signed T. Walker's/Patent/Harpoon/Ship Log/A.1/ London. Also signed on the tail blades with the initials "T W" and "J.B."

The mechanical log recorded the speed and distance run by a ship. It was thrown overboard, and as it was towed astern of the ship, the five-finned section of the mechanism rotated and registered the revolutions on the dials on its side, indicating as such the number of nautical miles sailed, in hundreds, tens, and ones. Thomas Walker (1805-71) and his son, also Thomas (1837-1921), refined the 1802 ship log by Edward Massey (1768-1852) and took their own patent for this "A1 Harpoon Log" in 1861. Each of the five fins at the back is inscribed with an anchor above the letters "T W" (for Thomas Walker).
Ref. Randier, L'antiquaire de marine, Éditions maritimes et d'outre-mer, 1973, p. 83. - National Maritime Museum, Greenwich, London.
Joined: Copper fog horn, 35 cm. (2 pcs)