Of the Phenomena in 



Motion, the Spires at the Top ga- 

 thering clofe together, and adting 

 againft the Head of the Cafe, while 

 thofe at the Bottom advance pro- 

 portionally, and feem to be conti- 

 nually fucceeded by others out of 

 the Head of the Pifton ; which Suc- 

 ceffion I believe to be apparent 

 only, and not real, the Appearance 

 being owing to the Nature of the 

 Motion in the Screw : In the In- 

 terim the Sucker, and Cup or Bar- 

 rel, move gently on in the fame 

 Direftion ; and the inferior Part of 

 the Apparatus, which contains the 

 Semen, extends itfelf in Length pro- 

 portionably, with a Motion at the 

 fame Time upwards, which may be 

 perceived by an increafe of the Va- 

 cuity at the Bottom of the Cafe. 

 Soon after this the Top of the Screw, 

 with its incloling Tube, appears out 

 of the Head of the Cafe, and as 

 it is there faftened by its Liga- 

 ments begins to bend : The Mo- 

 tion of the whole continues thus 

 flow and gradual, till the Screw, 

 Sucker, and Cup have forced their 

 Way, and emerged totally, when at 

 that Inftant the Remainder of the 



Apparatus 



