Thomas Harrison Butler
Thomas Harrison Butler, DM, FRCS(Eng) (19 March 1871 – 29 January 1945) was a British ophthalmologist and amateur boat designer. He published various designs of small, traditionally built yacht and was particularly concerned with the boat's handling under sail. Medical career. Butler graduated with an MA from Corpus Christi College, Oxford in May 1902, and received a Doctorate of Medicine (DM) at the same time. He practiced in Coventry, Birmingham and Leamington Spa, where he had private practices. He spent most of his time, however, on unpaid hospital work. Boat designer. Harrison Butler was "a strong believer  in the 'metacentric shelf formula' to achieve good balance and handling under sail. The theory held that as a yacht heels under sail, its balance will depend on the immersed form of the hull, with different sections exerting varying degrees of buoyancy and aft sections possibly being more buoyant than forward sections. Metacentric shelf analysis plots the shifts in the varying buoyancies as a net value to windward or leeward and serves as a guide to achieving equal buoyancy in the dissimilar ends of a design. The work can now be done by computer, but when it was applied by  the brain, hand and eye of Dr. Harrison Butler it produced famously sweet-handling boats, in the age of heavy weather helm." In the days before computers, Harrison Butler was known to cut out paper cross sections of his hulls in order to calculate lines of symmetry and centres of mass. Boats built to his designs are noted for their sleek looks as well as their pleasant handling. He wrote two books, "Cruising Yachts: Design and Performance," and "An Illustrated Guide to the Slit-Lamp." and was the subject of a 1980s BBC TV documentary. Selected Designs. In addition to  those above, a number of other Harrison Butler designs were built over the years, including: The Harrison Butler Association. A Harrison Butler Association was formed in 1973 for anyone interested in his designs. It aims to keep track of Harrison Butler boats worldwide and help owners keep in touch. It holds two meetings and produces two newsletters annually. Trivia. Harrison Butler was the father-in-law of actress Joan Hickson.