Microscopical Essays, 321 



c - All thofe fpcculations concerning lines and numbers, fo 

 ardently purfued, and fo exquifitely conducted by the Grecians* 

 what did they aim at ? or what did they produce for ages? a 

 little arithmetic, and the firft elements of geometry, were all they 

 had need of. This Plato alferts ; and though, as being himfelf an 

 able mathematician, and remarkably fond of thefe Sciences, he 

 recommends the ftudy of them ; yet he makes ufe of motives 

 that have no relation to the common purpofes of life. 



" When Kepler, from a blind and ftrong impulfe, merely to 

 find analogies in nature, difcovered that famous one between 

 the diftance of the feveral planets from the fun, and the periods 

 in which they complete their revolutions, of what importance 

 was it to him or the world ? 



" Again ; when Galileo, pufhed on by the fame irrefifiible 

 curiofity, found out the law by which bodies fall to the earth, 

 did he, or could he, forefee that any good would come from his 

 ingenious theorems ? or was any immediate ufe made of them ? 



et Yet had not the Greeks pufhed their abflracl: fpeculations fo 

 far, had not Kepler and Galileo made the above-mentioned dis- 

 coveries, we never could have feen the greateft work that ever 

 came from the hands of man, Sir Ifaac Newton's Principia. 



" Some obfcure perfon, whofe name is not fo much as known, 

 diverting himfelf idly, as a ftander-by would have thought, with 

 trying experiments on a feemingly contemptible piece of {tone, 

 found out a guide for mariners on the ocean, and fuch a guide as 

 no fcience, however fubtil and fublime it's fpeculations may be, 



R r > however 



