ON THE HISrORY OF MECHAlTlCS. 23T 



the extremities of* the diameter of a circle, and meeting in any other part of 

 its circumference form with each other a right angle. Thales was one of the 

 seven whom antiquity distinguished by the appellation of wise men ; he 

 flourished about 600 years before the Christian era, and he was the father of 

 the Ionian school, the members of which, in subsequent times, devoted them- 

 selves more particularly to the study of moral than of natural philosophy. 



The Italian school, on the contrary, which was founded by Pythagoras, 

 appears to have been more inclined to the study of nature and of its laws; al- 

 though none of the departments of human knowledge were excluded from 

 the pursuits of either of these principal divisions of the Grecian sages, until 

 Socrates introduced, into the Ionian school, a taste for metaphysical speculations, 

 which excluded almost all disposition to reason coolly and clearly on natural 

 causes and effects. To Pythagoras, philosophy is indebted for the name 

 which it bears; his predecessors had been in the habit of calling themselves 

 wise; he chose to be denominated a lover of wisdom only. He had studied 

 under Pherecydes, and Pherecydes under Pittacus: but with respect to mathe- 

 matical and mechanical researches, it does not appear that either of his teach- 

 ers had made any improvements. On his return from his travels in Egypt and 

 th'fe East, in the time of the last Tarquin, about 500 years before Christ, he 

 found his native country Samos under the dominion of the tyrant Polycrates, 

 and went as a voluntary exile to seek a tranquil retreat in a corner of Italy. 

 At Croto, says Ovid, he studied and taught the laws of nature. 



" From human view what erst had lain concealed 

 His piercing mind to open light revealed ; 

 To patient toil his ardent soul constrained. 

 Of Nature's richest stores possession gained : 

 And thence, with glowing heart and liberal hand, 

 He dealt her treasures o'er the listening land. 

 The wondering crowd the laws of nature hears. 

 And each great truth in silent awe reveres. " 



However erroneous the opinion may be, that Pythagoras was acquainted 

 with the laws of gravitation, it is certain that he made considerable improve- 



