massively forged English notes. In 1819, with his printing business partner, Gideon Fairman, they employed Asa Spencer and went to England at Charles Heath's urging in an attempt to win the £20,000 reward for "unforgable notes". Sample notes were shown to the Royal Society president Sir Joseph Banks. They set up shop in England, and spent months on example banknotes, but unfortunately for them, Banks thought that the inventor should be English by birth. Printing English notes ultimately proved a success and was carried out by Perkins in partnership with the English engraver-publisher Charles Heath and his associate Gideon Fairman. Together they formed the partnership Perkins, Fairman and Heath. Heath and Perkins also had support from their brothers. Perkins, Fairman and Heath was later renamed, when his son-in-law, Joshua Butters Bacon, bought out Charles Heath and the company was then known as Perkins, Bacon. Perkins Bacon provided banknotes for many banks, and foreign countries with postage stamps. Stamp production started for the British government in 1840 with the 1d black and the 2d blue postage stamps, which incorporated an anti-forgery measure in the form of a complicated background produced by means of the rose engine. Their stamps were the first known preglued stamps. Also concurrently, Jacob's brother ran the American printing business, and they made money on important fire safety patents. Charles Heath and Jacob Perkins worked together and independently on some concurrent projects. Hermetic tube Jacob Perkins has patents for Heating and Air Conditioning technology. In 1829–30, he went into partnership with his second son Angier March Perkins, manufacturing and installing central heating systems using his hermetic tube principle. He also investigated refrigeration machinery after discovering from his research in heating that liquefied ammonia caused a cooling effect. Steam power In 1816, Jacob Perkins had worked on steam power with Oliver Evans in Philadelphia. In 1822 he made an experimental high pressure steam engine working at pressures up to . This was not practical for the manufacturing technology of the time, though his concepts were revived a century later. Perkins' boiler was the first example of a flash boiler and one of the first examples of a contra-flow heat exchanger. The water-tube boiler consisted of heavy cast iron straight, square-section water-tubes across the firebox, joined by unheated pipes outside it. These tubes were arranged in three layers, with water pumped into the upper layer and steam extracted at the