Jonathan Hornblower

Jonathan Hornblower (1753 to 1815) was an English pioneer of steam power, the son of Jonathan Hornblower the Elder and brother of Jabez Carter Hornblower, two fellow pioneers of steam. He invented the compound steam engine in 1781 and patented it that year: a two cylinder design in which steam first expands in a high-pressure cylinder and then again in a low-pressure cylinder, an evolution from the single-cylinder condensing engines of Newcomen and Watt. Litigation with Boulton and Watt over patents stopped him from developing it, and the principle was not revived until Arthur Woolf in 1804. He also patented a rotary engine in 1798, invented the double-beat steam valve around 1800, and developed a steam-wheel in 1805.