EMBELLISHMENTS. 469 



found advantageous to begin, at the reservoir or cistern 

 with pipes of a diameter somewhat greater than those 

 which dehver the water to the quills, because the water, in 

 a pipe of uniform diameter of so great a length, is found 

 to lose much of its strength, and become what is tech 

 nically called sleepy : while the different sizes quicken it, 

 and redouble its force. For example, in a conduit pipe of 

 1800 feet in length, the first six hundred feet may be laid 

 with pipes of eight inches in diameter, the next 600 feet 

 with pipes of six inches in diameter, and the last 600 feet 

 with pipes of four inches in diameter. In conduits not 

 exceeding 900 feet, the same diameter may be continued 

 throughout. When several jets are to play in several 

 fountains, or in the same, it is not necessary to lay a fresh 

 pipe from each jet to the reservoir ; a main of sufficient 

 size, with branch pipes to each jet, being all that is required. 

 Where the conduit pipe enters the reservoir or cistern, it 

 ought to be of increased diameter, and the grating placed 

 over it to keep out leaves and other matters which might 

 choke it up, ought to be semi-globular or conical ; so that 

 the area of the number of holes in it may exceed the 

 area of the orifice of the conduit pipe. The object is to 

 prevent any diminution of pressure from the body of 

 water in the cistern, and to facilitate the flow of the 

 water. Where the conduit pipe joins the fountain, there, 

 of course, ought to be a cock for turning the water off and 

 on ; and particular care must be taken that as much water 

 rr.ay pass through the oval hole of this cock as passes 

 through the circular hole of the pipe. In conduit pipes, all 

 elbows, bendings, and right angles should be avoided as 

 much as' possible, since they diminish the force of the 

 water. In very long conduit pipes, air-holes formed by 



