lower, giving that contra-flow arrangement. In 1927, Loftus P. Perkins, a descendant, lectured on these boilers and displayed a copper pipe, apparently from a engine of a type that was in use up until 1918. Perkins' high-pressure steam technology was also used in another invention, the steam gun. This was an early fully automatic machine gun, powered by steam rather than by gunpowder. Although not the first automatic firearm, it was the first to also have a high magazine capacity of more than a handful of rounds. It operated with musket balls at a cyclic firing rate of 1,000 rounds per minute. It is reported to have been rejected by the Duke of Wellington as 'too destructive'. In 1827 he became the first person in England to use a uniflow steam engine. A locomotive on the South Eastern Railway was converted to the Uniflow system in 1849, although it is not known whose idea this was. Perkins applied his Hermetic tube system to steam locomotive boilers and a number of locomotives using this principle were made in 1836 for the London and South Western Railway. This was a very early example of a high pressure steam locomotive. National Gallery of Practical Science In 1832 Perkins established the National Gallery of Practical Science on Adelaide Street, West Strand, London. This was devoted to showing modern inventions. A popular feature was his steam gun, which did not find favour with the military. Refrigeration Perkins is credited with the first patent for the vapor-compression refrigeration cycle, assigned on August 14, 1834 and titled, "Apparatus and means for producing ice, and in cooling fluids". The idea had come from another American inventor, Oliver Evans, who conceived of the idea in 1805 but never built a refrigerator. The same patent was granted in both Scotland and England separately. Financial problems detailed Jacob Perkins and Charles Heath had many business successes, but also had financial difficulties, but usually not at the same time. The accounting records for their printing business shows the two borrowed from the business, and sold shares back and forth when necessary in any and all business ventures, and kept detailed records. This professional relationship ended when Jacob's son-in-law, Joshua Butters Bacon, bought out Charles Heath's share of their shared printing business, which then became Perkins Bacon. At one point he became involved in lawsuits and had to close his engine factory. Patents