presents
(with help from our friends @)
MEMBRANE.COM
Christian Huygens ( April 14, 1629 -- 
                          July 8, 1695)
published in  1690 Discours de la cause de la
                         pesanteur ("Discourse on the Cause of Gravity", dating at least
                         to 1669) proposing a mechanical explanation of gravity based on
                    
                             Cartesian vortices.