"Sir W. Monson had orders to pursue her, which he did with that celerity, that she was taken within four miles of Calais, shipped in a French bark of that town, whither she was bound." A. GRAYAN. NEWTON, CICERO, AND GRAVITATION. (Vol. v., p. 344.) "When shall we three meet again?" Let no one smile at your correspondent's question, for the common mode of stating Newton's claim makes it natural enough to ask whether the ancients were aware that bodies fall to the earth, and to produce proof that they had such knowledge. But Cicero had more: he not only knew the fall of bodies, but he had a _medius locus mundi_, or _centrum mundi_, as it was afterwards called, to which bodies must fall. This was his law of gravitation, and that of his time. Without describing the successive stages of the existence of this centre, it may be enough here to state, that a part of Newton's world-wide renown arises from his having cashiered this immovable point from the solar system, and sent it on its travels in search of the real centre of gravity of the whole universe. Newton substituted, for the old law of gravitation _towards a centre_, his law of _universal_ gravitation, namely, that _every_ particle gravitates towards every other. There had been some idea of such a law in the minds of speculative men: it was Newton who showed that one particular law, namely, that of the inverse square of the distance, would entail upon a system, all whose particles are subject to it, those very motions which are observed in our system. Cicero would have been startled to know that, when a body falls towards the earth, the earth rises towards it, _medius locus_ and all: not quite so fast, it is true, nor so far. But it must not be supposed that we could move our earth any distance in course of time by continually dropping heavy weights upon it; for the truth is, that when the weight is raised the earth is a little lowered, or at least made to move the other way. Archimedes said that, with a place to stand on, he could move the earth; not aware that he was doing it at the time he spoke, by the motion of his arm. M. May I ask your correspondent S. E. B. where he has discovered that the _world-wide reputation_ of Newton was founded upon a notion of his being the first person who pointed out that bodies are attracted, or seem to be attracted, towards the centre of the earth? and, on the other hand, what traces there are in Cicero of the _real_ "law of gravity," which Newton _did_ discover, and with such immense labour demonstrate and illustrate, namely, that attraction (that is, not to the centre of the earth or world in particular, but between every particle of matter and the rest) varies inversely as the square of the distance?