III. Observations of the late total eclipse of the sun on the 22d of April last past, made before the Royal Society at their house in Crane Court in Fleet-street, London. By Dr. Edmund Halley, Reg. Soc. Secr. With an account of what has been communicated from aboard concerning the same

Abstract

Though it be certain from the principles of astronomy, that there happens necessarily a central eclipse of the sun in some part or other of the terraqueous globe, about twenty eight times in each period of eighteen years;