Supplement to the practical rules for ascertaining the deviations of the compass caused by the ship's iron: being instructions for the computation of a table of the deviations of the ship's compass, from observations made on 4, 8, 16, or 32 points, and a graphic method of correcting the deviations of a ship's compass
Smith Archibald | printed for the Hydrographic office, Admiralty | 1855