Anaximander

Anaximander, a Greek mathematician and philosopher, successor of Thales as head of the physical school of philosophy, was born at Miletus, 611 B.C., and died in 547. He is said to have discovered the obliquity of the ecliptic, and he certainly taught it. He appears to have applied the gnomon, or style set on a horizontal plane, to determine the solstices and equinoxes. The invention of geographical maps is also ascribed to him. As a philosopher, he speculated on the origin (archê) of the phenomenal world, and this principle he held to be the infinite or indeterminate (to apeiron). From it he conceived all opposites, such as hot and cold, dry and moist, to proceed through a perpetual motion, and to return to it again. Of the manner in which he imagined these opposites to be formed, and of his hypothesis concerning the formation of the heavenly bodies from them, we have no sufficient information. Some of his particular opinions were, that the sun is in the highest region of the heavens, is in circumference twenty-eight times greater than the earth, and resembles a cylinder from which flow continual streams of fire; also that the earth is of the form of a cylinder, that it floats in the midst of the universe, and that it was formed by the drying up of moisture by the sun.