PERKINS, Jacob (1766-1849), inventor and physicist, was born at Newburyport, Massachusetts, in 1766, and apprenticed to a goldsmith. He soon made himself known by a variety of useful mechanical inventions, and in 1818 came over to England with a plan for engraving bank-notes on steel, which, though it did not find acceptance at once, ultimately proved a signal success, and was carried out by Perkins in partnership with the English engraver Heath during the rest of his long business life. Perkins continued to be fertile of inventions, and his steam-gun, exhibited in 1824, attracted much attention, though the danger attending the use of highly-compressed steam prevented its practical adoption. His chief contribution to physics lay in the experiments by which he proved the compressibility of water and measured it by a piezometer of his own invention; see vol. vii. p. 801, and PhU. Trans., 1820, 1826. He retired in 1834, and died in London, 30th July 1849.