the centre of the world, whether you show it to have decreased by the earth's obliquity of motion. One may see then how from inexact observations men rashly conceive new and contradictory opinions and imagine absurd motions of the mechanism of the earth. For since Ptolemy only received certain latitudes from Hipparchus, and did not in very many places make the observations himself; it is likely that he himself, knowing the position of the places, formed his estimate of the latitude of cities from probable conjecture only, and then placed it in the maps. Thus one may see, in the case of our own Britain, that the latitudes of cities are wrong by two or three degrees, as experience teaches. Wherefore all the less should we from those mistakes infer a new motion, or let the noble magnetick nature of the earth be debased for an opinion so lightly conceived. Moreover, those mistakes crept the more readily into geography, from the fact that the magnetick virtue was utterly unknown to those geographers. Besides, observations of latitudes cannot be made sufficiently exactly, except by experts, using also finer instruments, and taking into account the refraction of the lights.
CHAP. III.
On the magnetick diurnal revolution of the Earth's globe,
as a probable assertion against the time-honoured
opinion of a Primum Mobile.
mong the ancients Heraclides of Pontus and Ecphantus, afterwards the Pythagoreans, as Nicetas of Syracuse and Aristarchus of Samos, and some others (as it seems), used to think that the earth moves, and that the stars set by the interposition of the earth and rose by her retirement. In fact they set the earth moving and make her revolve around her axis from west to east, like a wheel turning on its axle. Philolaus the Pythagorean would have the earth to be one of the stars, and believed that it turned in an oblique circle around fire, just as the sun and moon have their own courses. He was a distinguished mathematician, and a most able investigator of nature. But after Philosophy became a subject treated of by very many and was popularized, theories adapted to the vulgar intelligence or based on sophistical subtility occupied the minds of most men, and prevailed like a torrent, the multitude consenting. Thereupon many valuable discoveries of the ancients were rejected, and were dismissed to perish in banishment; or at least by not being further cultivated and developed became obsolete. So that Copernicus (among later discoverers, a man most deserving of literary honour) is the first who attempted to illustrate the φαινόμενα of moving
