Magnetising metalsIn 1744, Gowan Knight presented his research on magnetising metals to the Royal Society. The method he discovered for permanently magnetising hard steels. The use of steel instead of soft iron greatly improved the otherwise crude compass needles used by England's Royal Navy, which then had a much longer magnetized life. Knight took out a patent for his compass in 1766. He devised better ways to suspend compass needles, and introduced the rhomboid shape now common for compass needles.Reference: Philosophical Trans., No. 474, p. 161 |