430 Difcbarge of Fluids [Book VII. 



of one inch, becaufe the areas of circles are as the 

 fquares of their diameters) : 



i X \/ 4: 4 X \/ 9 :: 5436 : x 



Or at length 

 2 : 12 :: 5436 : 32616 

 12 



2)653232 



Therefore 32616 cubic inches of water 

 will flow from an aperture of two inches in diameter 

 in one minute, the orifice being made nine inches 

 from the furface, which is fuppofed to be kept at that 

 height the whole time. 



If a veffel of a prifmatic form is filled with water, 

 and permitted to empty itftlf en-.l. -ly through an ori- 

 fice at the bottom, and the time that it confumes in 

 emptying itfelf is obferved ; and if afterwards, having 

 replenifhed the veflel, the water is made to flow through 

 the fame aperture, the veffel being kept full the whole 

 time, there will run out in this fecond inftance, flu ring 

 the fame time that the veflel took to empty itfelf at 

 firft, a quantity of water double that which runs out 

 in the firft cafe, for the abftracTion of the water pro- 

 duces a kind of funnel, which in this laft cafe does nor 

 take place. 



We often perceive water flow through lateral aper- 

 tures, which, though fmall in companion to the width 

 of the refervoirs, cannot be regarded as Lining all their 

 .points at an equal diftance from the furface of the 

 fluid; fuch, for example, as the apertures through 

 which water fometimes flows in mills. The common 

 method of determining the quantity difcharged is as 

 follows : fuppofe, in the firft place, the aperture to be 

 flopped up by a plate of metal, which is perforated 



with 



