A lovely copy, remarkably preserved in two volumes in its original vellum, of this most interesting popular work on sundials by Pierre Bobynet, printed in the town of La Fleche undoubtedly for the students of the celebrated Jesuit college there. Indeed the approbation and permission, signed by Jean Filleau, provincial of the Society gives permission to print the work to George Griveau on behalf of the College Royal de La Fleche. The Jesuit father Pierre Bobynet [1593-1668] was a professor of philosophy and rector of La Flèche and several other Jesuit colleges. He was born in Montluçon to a relatively poor family, his father was a tanner, though he was recognised very young as having aptitude, and joined the Jesuits at the age of 12. He became rector of the Jesuit colleges at Moulins and Quimper before he moved to La Fleche, where he taught Philosophy, Theology, and Rhetoric for over 24 years. It seems, however, his passion was for mathematics. This was his first published work and he went on to publish two more on the subject and another on longimetry. The work is a very complete treatise on sundials with sections on the terminology used, the instruments required in their fabrication, and theoretical and practical gnomonics describing numerous wall, garden or pocket sundials. Bobynet s work was one of the first to discuss Dialing scales which were used to lay out the face of a sundial geometrically. They were first proposed by Samuel Foster in 1638, and later produced by George Serle and Anthony Thompson in 1658 on a ruler. There are two scales: the latitude scale and the hour scale. They were used to draw all gnomonic dials and reverse engineer existing dials to discover their original intended location. These scales remained virtually unchanged for 250 years. Most copies of this work were bound as a single volume or are found without the plates. This copy is remarkably preserved in its original vellum as a two volume set. We have not been able to discover the P. Trouard de Riolle but it seems probable that he was the first owner of the work and was probably a student at the Royal College at La Fleche.
