Ip8 The PraBice Part IL 



made oppofite one fo the Other^ or elfe have feveral other 

 fmall Quills folder'd oh upon them. 



Some pretend^ that Spouts of Water play better when the 

 Mariotte, Quills are pierced with a fmgle Hole through a pretty thick 

 f^^^ Plate, than when they are railed in a Cone^ becaufe there is 

 .3 ? 337' i^j-^ Fridion made, and lefs Refiftance at the Mouth of it. 



'Tis certain, that the bigger the Pipes are, the better 

 the Water plays ^ and 'tis the Life of fine Water-works to 

 be well fed, which Ihould be by one continued Length of 

 Pipe, all of a Size from the Referver to the very Quill, with- 

 -oiit any Diminution ^ this fufnilhes more Water, and gives 

 , a greater Weight to the Spout, which without it appears 

 choaked, and confined too much. 



There are fome of a quite contrary Opinion, who 

 imagine, that in a Pipe of loo Fathom long, the firft 50 

 Fathom from the Referver fhould be bigger than the laft 

 50 to the Quill, which they pretend Ihould be lelfen'd 

 about an Inch in Diameter to the end, fay they, that the 

 Water may begin to be forced and contracted at fomewhat 

 more Diflahcein the Pipe, which ought always to go dinii- 

 nilhing to the very iffuing out of the Water : But this is a 

 veiy wrong Notion in the Cafe of Fountains, for it is fuf- 

 ficient to contract and force the Water in the Trunk or Co- 

 lumh of the Spout, and in the Quill, without diminilhing 

 the Size of the Pipe. 



Th E RE is but one Cafe where the Diameter of the Wa-^ 

 ter-Pipes ought to be diminini'd, which is, when they are of 

 ^ very great Length, as three or four hundred Fathom > it 

 is then convenient to lay three feveral Sizes of Pipe ^ for 

 whereas without it, the Water in fo great a Length would 

 deep as it were by the way, and lofe much of its Strength ; 

 thefe different Sizes quicken it, and redouble its Force : 

 For Example, in a great Conduit of 300 Fathom long, you 

 fhould lay the firft hundred Fathom with Pipe of eight Inches 

 Diameter, the next 100 with fix Inches, and the laft with 

 four Inches j but in Conduits of 100 or 150 Fathom, the 

 fame Diameter fliould be continued thg whole Length to the 

 yery-QuilL 



When 



