An unusual tradesman's miniature cut-away model of a Pulsometer steam pump The Pulsonometer Engineering Company Limited, London, circa 1880 Finely cast and hand finished in gilt and silvered brass with central glazed cavity enclosing ball-bearing valve with two further pear-shaped chambers with ball-valves behind angled plates engraved THE, PULSOMETER ENGINEERING, COMPANY LIMITED, LONDON to the base and with a third shaped enclosed chamber rising through the centre, on flanged foot piped to each of the two main chambers, 8cm (3.125ins) high; in original blue velvet and silk lined leather covered shaped protective case. The Pulsometer steam pump is a pistonless pump which was patented in 1872 by American Charles Henry Hall. In 1875 a British engineer bought the patent rights of the Pulsometer and it was introduced to the market soon thereafter. The invention was inspired by the 'Savery steam pump' invented by Thomas Savery. This extremely simple pump was made of cast iron, and had no pistons, rods, cylinders, cranks, or flywheels. It operated by the direct action of steam on water. The mechanism consisted of two chambers. As the steam condensed in one chamber, it acted as a suction pump, while in the other chamber, steam was introduced under pressure and so it acted as a force pump. At the end of every stroke, a ball valve consisting of a small brass ball moved slightly, causing the two chambers to swap functions from suction-pump to force-pump and vice versa. The result was that the water was first suction pumped and then force pumped. The current lot is a finely made cut-away model of the Pulsometer pump most likely used by a selling agent to explain its unique operation to interested parties.