An essay on comets: in two parts, the whole interspersed with observations and reflections on the sun and primary planets

Part I. Containing an attempt to explain the phaenomena of the tails of comets, and to account for their perpetual opposition to the sun, upon philosophical principles

Part II. Pointing out some important ends for which these tails were probably designed, wherein it is shown that, in consequence of these curious appendages, comets may be inhabited worlds, and even comfortable habitations, notwithstanding the vast excentricities of their orbits.