An essay on comets in two parts. Part I. Containing an attempt to explain the ph nomena 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 there tails were probably defigned. This book, "An essay on comets in two parts", by A. Oliver, is a replication of a book originally published before 1772. It has been restored by human beings, page...