In 1639, nine years after Kepler’s death, there appeared in Paris a remarkably original but little needed treatise on the conic sections.* It was written by Gerard Desargues, an engineer, architect, and onetime French army officer, who was born in Lyons in 1593 and who died in the same city about 1662. The work was so generally neglected by other mathematicians that it was soon forgotten and all copies of the publication disappeared. Two centuries later, when the French geometer Michel Chasles (1793-1880) wrote his still standards history of geometry, there was no means of estimating the value of Desargues’ work. Six years later, however, in 1845, Chasles happened upon a manuscript copy of the treatise, made by Desargues’ pupil, Philippe de la Hire (1640-1718), and since that time the work has been regarded as one of the classics in the early development of authentic projective geometry.