Page 342 - 89 history of astronomy_opt
P. 342
governing the motions of the heavenly bod-
ies, there may yet be a resisting medium in
space, and there may be electric and mag-
netic forces to deal with. There may, fur-
ther, be cases where the effects of luminous
radiative repulsion become apparent, and
also Crookes’ vacuum-effects described as
”radiant matter.” Nor is it quite certain
that Laplace’s proofs of the instantaneous
342
