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.
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.
Dom Bédos's work, in four folio volumes, contains great historical detail about eighteenth-century organ building, and is still referred to by modern organ-builders.
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.