Jacob Perkins (9 July 1766 – 30 July 1849) was an American inventor, mechanical engineer and physicist. Born in Newburyport, Massachusetts, Perkins was apprenticed to a goldsmith. He soon made himself known with a variety of useful mechanical inventions and eventually had twenty-one American and nineteen English patents. He is known as the father of the refrigerator. He was elected a Fellow of the American Academy of Arts and Sciences in 1813 and a member of the American Philosophical Society in 1819. Early life Jacob went to school in Newburyport until he was twelve and then was apprenticed to a goldsmith in Newburyport named Davis. Mr. Davis died three years later and the fifteen-year-old Jacob continued the business of making gold beads and added the manufacture of shoe buckles. When he was twenty-one he was employed by the master of the Massachusetts mint to make a die for striking copper pennies bearing an eagle and an Indian. Innovations Nail machines In 1790, at the age of 24, in Byfield, he created machines for cutting and heading nails. In 1795, he was granted a patent for his improved nail machines and started a nail manufacturing business on the Powwow River in Amesbury, Massachusetts. Cannon borings During the War of 1812 he worked on machinery for boring out cannons. Hydrostatics He worked on water compression and invented a bathometer or piezometer to measure the depth of the sea by its pressure. Engraving Perkins created some of the best steel plates (as noted from English Engravers) for engraving, and started a printing business with engraver Gideon Fairman. They began with school books, and also made bank notes that were difficult to counterfeit. In 1809 he bought the stereotype technology (an aid in large-batch printing of bank notes that were difficult to counterfeit) from Asa Spencer, and registered the patent, and then employed Asa Spencer. Perkins made several important innovations in printing technology, including new steel engraving plates. Using these plates he made the first known steel engraved USA books (The Running Hand, school books, 8 pages each). He then made notes for a Boston Bank, and later for the National Bank. In 1816 he set up a printing shop and bid on the printing of currency for the Second National Bank in Philadelphia. His quality printing of American bank notes attracted attention of the Royal Society who were busy addressing the problem of