224 MICHAEL A. HOSKIN 



substance of it; for gravity is never in proportion to the super- 

 ficies of bodies or of any corpuscles, but always to the solid 

 quantity of them. Wherefore we ought no more to enquire 

 how bodies gravitate, than how bodies began first to be 

 moved." ^^ 



In the other two notes Clarke gives a taste of the power of 

 the Newtonian conception. In the first he outlines, informally, 

 how gravity explains the first two Keplerian laws of planetary 

 motion ^*; in the second he follows Halley in using gravity to 

 explain the motion of the tides .^^ Here at last the English 

 undergraduate was given a glimpse of the power of the New- 

 tonian theory; one wonders what continental readers made of 

 these notes when they were republished in Amsterdam in 1708, 

 no longer hidden at the back of the book, but displayed as 

 footnotes to Rohault's text.^*^ 



Although in the 1702 notes Clarke's views are unmistakable, 

 surprisingly large sections of the Rohault text are still allowed 

 to pass unchallenged. Sometimes this is because Clarke does 

 not yet go out of his way to pick quarrels with his author — 

 for example, he does not exploit Newton's teaching on comets 

 as an argument against the Cartesian vortices — but sometimes 

 it is because Clarke is still hampered by Newton's failure to 

 publish a more widely-ranging account of his views. 



In 1704, however, Newton's Opticks at last appeared, and 

 it was Clarke himself who prepared the Latin translation of 

 1706.^" When a new edition of his Rohault translation was 

 published four years later, Clarke made numerous references 

 in his notes to the Opticks, many of them accompanied by 



^^ Notes, pp. 81-83. 



''* Notes, pp. 70-72. An improved version of this note, with some mathematics, 

 was published in the 1723 edition. 



*^ Notes, pp. 83-85. 



'" The influence, if any, of this early popularization of Newtonian cosmology on 

 the continent does not appear to have been studied. Clarke's forthright views on the 

 nature of attraction are unlikely to have commended themselves to Cartesian readers. 



*''With additional queries, in particular the one which later became Query 31, 

 from which Clarke quotes nearly two dozen passages in his 1710 notes. 



