21

Hydraulics.

taln^ which playing from the small Orifice

of an Adjutage at the Bottom, will ip° ut

J 0 -vrerv

serving up his own Son at a Feast of the Gods, to standin a River of Hell up to his Chin in Water, which yethe is not permitted to sip to quench his eternal Thirst,

Now this Tantalus is the Man in the Glass, with a Sy-phon concealed in his Body, beginning in the Bottom,of one of his Feet, and ascending to the upper Part orhis Breast ; there it makes a Turn, and deicends throthe other Leg on which he stands, and from thencedown through the Foot of the Glass, where it runsout, and causes the Water to subside in the Glass,as soon as it rises to the sleight of the Syphon, or tothe Chin of the Man ; and thus aptly expresies the

■Fable.

6. This Syphon may very easily be concealed also inthe Handle of a common Pint Pot or Cup,^ and thenit is called the Tantalus-Cup : For the l op of theHandle being a little below the Top or Run of theCup, and the lowest Part of the Handle or Syphon be-low the Bottom or Orifice by which it communicateswith the Cup, will cause the Cup to have the Propertyof emptying itself when filled to the Brim; as is easyto understand from what has been said above.

Scholium.

7- The Nature of .this Syphon, or the hydraulscLawof Fluids, on which it depends, was not understood bythe Ancients ; for though we read surprising Accountsof the Roman Aquæducts and Pipes, by which theyconvey’d Water to the Distance sometimes of five orsix Miles, yet we find no mention made of any otherthan horizontal and descending Pipes or Ducts, andnever of any rising or ascending. . If the Water was tobe convey’d where a Valley interposed, they with gteatExpence and Labour constructed a Water-Gourfe overthe same, supporting it with vast Piles and Archessometimes frorp the Depth of an xoo beet. Whereas

a single Pipe laid ever the Vale would have done the■ c, 2 Business