The Importance of Mathematics in Seafaring

Before there was an accurate seafaring clock, the sailor seeking his bearings had to be a trained mathematician. The accepted way to find longitude at sea was by precise observations of the moon, which required refined instruments and subtle calculations. An error as small as 5' in observing the moon meant an error of 2V2. degrees of longitude, which on the ocean could be as much as 150 miles—enough to wreck a ship on treacherous shoals. Fatal miscalculation might come from a crude instrument, from an error in the nautical tables, or from the rocking motion of the ship.

This made the problem of longitude an educational as well as a technological problem. The great seafaring nations optimistically organized mathematics courses for common sailors. When Charles II set up a mathematics course for forty pupils at Christ's Hospital, the famous "Bluecoat" charity school in London, teachers found it hard to satisfy both the sailors and the mathematicians. The governors of the school, noting that Drake, Hawkins, and other great sailors had done well enough without mathematics, asked whether future sailors really needed it. On the side of mathematics, Sir Isaac Newton argued that the old rule of thumb was no longer good enough. "The Mathematicall children, being the flower of the Hospitall, are capable of much better learning, and when well instructed and bound out to skilful Masters may in time furnish the Nation with a more skilful sort of Sailors, builders of Ships, Architects, Engineers, and Mathematicall Artists of all sorts, both by Sea and Land, than France can at present boast of." Samuel Pepys, then Secretary to the Admiralty, had already set up a naval lieutenant's examination which included navigation and, following Newton's advice, naval schoolmasters were actually put on board ships to instruct the crew in mathematics.

Sailors had to be mathematicians in order to keep their bearings on the ocean.