FITNESS 17 



nomical phenomena. 1 And recent most re- 

 markable studies of the stars have enabled 

 astronomers to account for obscure events 

 in far distant parts of the universe by the 

 application of the principles of dynamics. 

 Similarly light, heat, and chemical energy, as 

 we know them, are unquestionably universal. 

 No doubt the manifestations of energy 

 within the sun and stars, like the accompany- 

 ing material phenomena there, can to-day 

 only be surmised. For aught we know, 

 these places may, as has been guessed, be the 

 birthplace of elements and the seat of mani- 

 festations of energy quite different from 



1 "What the Occasion of Sir Isaac Newton's leaving the 

 Cartesian Philosophy, and of discovering his amazing Theory 

 of Gravity was, I have heard him long ago, soon after my first 

 Acquaintance with him, which was 1694, thus relate, and of 

 which Dr. Pemberton gives the like Account, and somewhat 

 more fully, in the Preface to his Explication of his Philos- 

 ophy : It was this. An Inclination came into Sir Isaac's 

 Mind to try, whether the same Power did not keep the Moon 

 in her Orbit, notwithstanding her projectile Velocity, which 

 he knew always tended to go along a strait Line the Tangent 

 of that Orbit, which makes Stones and all heavy Bodies with 

 us fall downward, and which we call Gravity? Taking this 

 Postulatum, which had been thought of before, that such 

 Power might decrease, in a duplicate Proportion of the Dis- 

 tances from the Earth's Center." — "Memoirs of the Life 

 of Mr. WiUiam Whiston by Himself." London, 1749, Vol. I, 

 pp. 35-38. Quoted by Ball. "An Essay on Newton's Prin- 

 cipia." London, 1893, p. 8. 

 c 



