Matthew Piers Watt Boulton

Matthew Piers Watt Boulton
Portrait of Boulton by Sir Francis Grant, c. 1850
Born	(1820-09-22)22 September 1820 Mose Old Norton, Staffordshire, England
Died	30 June 1894(1894-06-30) (aged 73) London, England
Other names	M. P. W. Bolton
Alma mater	Trinity College, Cambridge
Occupations	Philosopher-scientist classicist inventor
Known for	Invention of the aileron translations of classical works scientific and other papers
Notable work	On Aërial Locomotion (1864)
Spouses	Frances Eliza Cartwright ​ ​ (m. 1845; died 1864)​ Pauline Gleissberg ​ (m. 1864)​
Children	Four daughters and two sons
Parents	Matthew Robinson Boulton Mary Anne Wilkinson
Relatives	Matthew Boulton (grandfather) William Ralph Cartwright (father-in-law)

Matthew Piers Watt Boulton (22 September 1820 – 30 June 1894), also published under the pseudonym M. P. W. Bolton, was a British classicist, elected member of the UK's Metaphysical Society, an amateur scientist and an inventor, best known for his invention of the aileron, a primary aeronautical flight control device. He patented the aileron in 1868, some 36 years before it was first employed in manned flight by Robert Esnault-Pelterie in 1904.

Boulton was the son of Matthew Robinson Boulton, and as well the grandson of Matthew Boulton, who founded the Soho Manufactory and the Soho Mint. His grandfather also co-founded the Soho Foundry with James Watt, which employed steam engines of the latter's design. Born into a family of significant wealth and means, M. P. W. was broadly educated in the classics, philosophy and sciences, subsequently becoming well versed in steam engine design, and then transferring his interest to the basic conceptual designs of jet propulsion and rocket motors. However, whatever personal interest he held in the foundry's operation and the coinage mint he inherited from his father soon waned, and he subsequently closed and sold the mint facility in 1850. Thereafter he conducted numerous studies, wrote a wide variety of papers and earned a number of patents, including for an aileron flight control system, various types of motive power engines and their components such as propellers and pumps, plus other works on solar heat, photography and more.

Despite being married twice and raising a large family, Boulton was described as reclusive by those who knew him. He was one of only five members of the Metaphysical Society who did not appear in the British Dictionary of National Biography. His Times obituary described him as "a gifted member of a gifted family ... [with] wide knowledge and sterling qualities"; however, he appears to have never sought notability nor gained it in his lifetime, and his accomplishments are known chiefly through his patents and published writings.