CENTURY VIII. 



not compense the weight of a stone more than the 

 weight of the aqua fortis. 



Experiment solitary touching the flying of unequal 

 bodies in the air. 



791. Let there be a body of unequal weight (as of 

 wood and lead, or bone and lead) ; if you throw it 

 from you with the light end forward, it will turn, and 

 the weightier end will recover to be forwards ; unless 

 the body be over-long. The cause is, for that the 

 more dense body hath a more violent pressure of the 

 parts from the first impulsion ; which is the cause 

 (though heretofore not found out, as hath been often 

 said) of all violent motions ; and when the hinder part 

 moveth swifter (for that it less endureth pressure of 

 parts) than the forward part can make way for it, it 

 must needs be that the body turn over : for (turned) 

 it can more easily draw forward the lighter part. 

 Galikeus 1 noteth it well, that if an open trough, 

 wherein water is, be driven faster than the water can 

 follow, the water gathereth upon an heap towards the 

 hinder end, where the motion began ; which he sup- 

 poseth (holding confidently the motion of the earth,) 

 to be the cause of the ebbing and flowing of the ocean : 

 because the earth over-runneth the water. Which 

 theory though it be false, yet the first experiment is 

 true. As for the inequality of the pressure of parts, 

 it appeareth manifestly in this : that if you take a body 

 of stone or iron, and another of wood, of the same 

 magnitude and shape, and throw them with equal 

 force, you cannot possibly throw the wood so far as 

 the stone or iron. 



1 See his Dialogi dei Sistemi Massimi. 



