Drawing after a bust of Jacob Perkins (1766-1849), Anglo-American inventor. Perkins was born in Newburyport, Massachusetts. At age 12 he was apprenticed to a goldsmith. When his master died just three years later Perkins took over the business. By age 24 he invented new machinery for making nails. During the War of 1812 against England he worked on gun manufacture, at the same time devising a piezometer for measuring the depth of water by its pressure. He moved to England in 1819, bringing the idea for steel engraving of plates for printing banknotes and postage stamps. He performed experiments with high-pressure steam and made important contributions in understanding the compressibility of water. By 1830 he was in partnership with his son making central heating systems based on heat pipes (hermetic tubes) and in 1834 patented the vapour-compression cycle for refrigerators.