20

Hydraulics.

From the Pressure of the superior Fluidwe have the Invention of a Natural Foun-tain^

G or I, therefore it can rise no higher in the Vestedthan those bended Parts of the Pipe. Again, becausethe Pressure of the Air upon the Water at FE in theV'esicI, and upon the Orifice at K is equal, therefore ifthe Orifice K were in the fame Level with the Bottomof the Vessel CL, the Water, having the fame Alti-tude E B and M L, would not run out at the OrificeL, but remain in Equilibria with that in the Vessel.

3. But, lastly, since the Orifice IC is below the Level,the Water at K will have a greater Altitude MK, andtherefore a greater Pressure, or Momentum , and so willprevail against the equal Pressure of the Air, and runout; and will continue to run out, till all the Waterin the Vessel be exhausted, because the Pressure of theAir upon the Surface F E will force the Water into thePipe to prevent a Vacuum , which must otherwise hap-pen in some Part thereof, which is absurd or contraryto Nature.

4. For suppose the Water were not to enter at B asfast as it runs out at K, there must happen a Separationof the Water in some Part of the Pipe, as at I for In-stance ; then the Water running out at K will causethe separated Part to descend from I towards L, andsince nothing can get into the Space between the sepa-rated Surfaces of Water at I and L, all that Space mustbe a pure Vacuum , and therefore the Water must be atrest in the Pipe between B and I, though the Pressureof the whole Atmosphere acts upon the Part at B, and ,nothing at all at the Part I to resist or counteract it,which is contrary to the Nature or Definition of a Fluid,as has been abundantly strewn in Annot. LIII. and all

the subsequent ones.

5. This bended Syphon is usually called a Tanta-lus, from the Semblance of the Experiment madewith a Man in a Glass to the. Case of Vantalus in theFable, who, according to the Poets, was sentenced forhis horrid and unnatural Crime of killing, boiling, and

serving