Apart from statics, about which I shall say nothing, there were three chief centres of interest in mechanics in the 1660's: the motions of pendulums; the laws of motion; the free fall of heavy bodies and the motion of projectiles.In the first the influence of Huygens was dominant; I have placed it so because it was of very lively contemporary concern. The second area of interest descended partly from Galileo and partly from Descartes; the third from Galileo alone. Perhaps one (...) should consider adding a fourth area, the investigation of central forces, but this in fact did not attract much attention as yet. (shrink)