Edward Massey was born into a family of Staffordshire clockmakers in the 1760s. However, by the end of his life, he had moved to London and identified himself as a ‘nautical instrument maker’. How did such a transition take place? And what effects did it have on the practice of navigation? Massey’s correspondence [RGO 14/31] with the Board of Longitude helps to answer these questions. It offers a window onto the shifting relationship between the practice of navigation at sea and the work of artisans back on the land.
Massey did not propose solutions aimed at the more famous problem of finding longitude. Instead, he manufactured a series of brass devices designed to measure the depth of water under a ship (a practice known as depth sounding). Traditionally, in order to measure the depth of water, a sailor would use a lead and line  (a simple coil of rope, knotted at set intervals, with a weight attached). In 1802 Massey offered an alternative. He patented his first mechanical sounding machine  . It consisted of two numbered dials, unmistakably the product of Massey’s clockmaking background, along with a rotor. This machine would have been attached to a standard lead and thrown overboard, the rotor spinning the dials before locking at the seabed. On hauling in, the depth in fathoms could be read off the dials as one would read a clock.
Massey’s wasn’t the first mechanical sounding design but it was the first to be widely adopted by the Royal Navy. Between 1807 and 1811, on the recommendation of the Board of Longitude, the Navy Board ordered 1750 of Massey’s machines. That’s at least one machine for every Royal Navy ship in commission during the Napoleonic Wars. As well as the profit from the sale of these machines, the Board of Longitude also awarded Massey a one-off reward of £200 [RGO 14/7] in July 1807. In this respect, he was one of the most successful applicants to the Board of Longitude under its broader remit to improve the general practice of navigation. Massey also manufactured a number of mechanical logs  (for measuring the speed of a ship) and improved escapement mechanisms  for watches.
But why was Massey so successful? Whether or not his sounding machine was more accurate than lead and line remained an open question. At the time, a number of navigators complained that Massey’s machine buckled in deep waters and was not suitable for use in strong currents. However, the Board of Longitude didn’t necessarily value Massey’s machine solely for its accuracy. Rather, Massey pitched his machine as aiding the reform of naval discipline. To take one example, naval authorities felt that negligence was hard to identify given that navigational practices often happened out of sight. Prior to the introduction of Massey’s machine, sounding was a case in point. Groups of sailors arranged themselves on the outside of the ship with a lead and line. This line would then be thrown overboard, out of sight of the officers on the quarterdeck. As the line was hauled in, one of the sailors would either observe or feel for the number of knots. The depth would then by relayed to an officer on deck in the form of a song: “by the mark ten” for ten fathoms.
All this changed with the introduction of Massey’s machine. The average sailor in the Royal Navy did not have experience of reading clock-like dials. For this reason, when Massey’s machine was hauled in, it would be taken to the quarterdeck so that an officer could read and record the depth measured. This simple change in practice made the results of sounding more visible to the officers. They no longer had to rely on a song emanating from out of sight. It also made sure that the officer on the quarterdeck took greater personal responsibility for the depths recorded, something the Admiralty considered crucial if they were to successfully court martial disobedient commanders. Massey was successful because his machine was both a navigational instrument and a disciplinary tool
History and Philosophy of Science
University of Cambridge