Chap. io, 



equally from all fides : that is, perpendicularly from the center 

 or the earth. And thus we Ice a motion fee on foot, of fome bo- 

 dies continually defending, and others continually alcending : 

 all in perpendicular lines, excepting thofe which follow the 

 courfe of lights reflexion. 



Again as foon as the declining fun groweth weaker or leaveth 

 our horizon , and that his beams vanishing do leave the 

 little horfemen which rode upon them, to their ownc temper 

 and nature (from whence they forced them) they finding them- 

 felves furroundedby a (mart dcfcending ftream,do tumble down, 

 again in the night, as faft as in the day. they were carried up - y 

 and crowding into their former habitations, they exclude thole 

 that they find had ufurped them in their abfence. And thus, all 

 bodies within reach of the funnes power,but efpecially our aire, 

 are in perpetuall motion ; the more rarified ones afcending,and 

 the dcnfe ones defcending. 



Now then ; becauie no bodies wherefoever they be (as we A dejl bo , 

 have already (hewed) have any inclination to move towards a placed in the 

 particular place, other wife then as they are directed and impel- ^,7 afcwdm^ 

 led by excrinfecall Agents : let us fiippofe that a body were pla- an -* defending 



j I-L L 1 U L L tlrcam, muftj- 



ced at liberty in the open^aire. And then calling whether it Hce j s ' 



would be moved from the place we fuppofe it in : and which 

 Way it would be moved ; we fhall find that it muft of necefluy 

 happen that it fhall defcend and fall down till it meet with 

 fome other grofle body to flay and fupport it. For although of 

 it felf it would move no way : yet if we fin d that any other body 

 ftriketh efficacioufly enough upon ic j we cannot doubt but thac 

 it will move that way which the ftriking body impelleth it. 

 Now,itis rtrucken upon on both fides(above and below)by the 

 afcending, and the defcending aromes.the rare ones, (hiking up- 

 on the bottome ofic, and driving it upwards, and the denier 

 onesj prcffing upon the top of it and bearing ic downwards. BJC 

 if you compare the imprcflions that the denfer atomes make, 

 with thofe that proceed from the rare ones ; ic is evident that 

 thcdenfe ones mull be the more powerfuil ; and therefore will 

 afluredly determine the motion of the body in the aire, that way 

 they go, which is downwards. 



Nor need we fear, left the littlcncfle'of the agents, or the fce- 

 blenefle of their ihokes, (hoald no: be fufficicnc to work this 



G effect; 



