Dom Bédos de Celles
François-Lamathe Dom Bédos de Celles de Salelles (24 January 1709 – 25 November 1779) was a Benedictine monk best known for being a master pipe organ builder. Life and work. He was born in Caux, Hérault, near Béziers, France. He was elected to the French Academy of Sciences at Bordeaux and correspondent of the academy at Paris in 1758. As a recognized organ-builder, he was called upon to carry out repairs and appraise and advise other organ-builders in many locations across France. In 1760 he published "La Gnomonique pratique ou l’Art de tracer les  cadrans solaires" under the patronage of the Jean-Paul Grandjean de Fouchy, Secretary of the Academy of Sciences and an authority in gnomonics and sundials. In 1766–78 he published his treatise "L'art du facteur d'orgues" (The Art of the Organ-Builder), which contains great historical detail about eighteenth-century organ building, and is still referred to by modern organ-builders. He is buried in the former Abbey (now Basilica) of Saint-Denis. Organ building in the mid 18th century. The 26 images below are taken from this work, kept in the St.Bernard's abbey library in Bornem. Horizontal Sundial  layout. The Dom Francois Bedos de Celles method (1790) otherwise known as the Waugh method (1973), enables a dial to be constructed on a narrower piece of paper or velum, than using Dürers (1525) method- though it is essentially the same for the hourlines 9 to 3. It relies on a theorem proved on 1682 by P. de la Hire. The method became well known when it was adopted by Waugh, as the construction method to be used for horizontal dials by Albert Waugh, in his 1973 book Sundials: their theory and construction.