■Water-pipes and Syphons Jrom disengaged Air, 115 



the ground will act ; or, at all events, in case of necessity, It 

 will be easy to sink it a few feet at the top, so as to bring it 

 within the range of thirty feet, but as a syphon is apt to ga- 

 ther air at the top, I propose a contrivance, which will effec- 

 tually remedy that inconvenience. 



r 



Stopcock. 



A A are two legs of a syphon. 



BB, the two ends turned up, so that the water cannot run out 



at either end. 

 C and E, stopcocks. 

 D, a ball containing about a cubit foot. 

 F, a funnel. 



GG are upon the same level. 

 H is the pipe bringing water to Princess Street. 



To carry this plan into effect, shut up the two ends BB,*and 

 open the cock C and E. Pour in water at F till the syphon is 

 quite full, then shut both cocks, leaving D andF full of water, 

 and open the ends BB. 



The syphon BAAB will not only constantly run when supplied 

 with water, but will continue charged though the supply should 

 be stopped. However, as a good deal of air is constantly sepa- 

 rating itself from water in pipes, it will of course collect imme- 

 diately below C ; and to get rid of this, it will be necessary to 

 let it out, perhaps once a-week, but for safety it can be let out 

 every second day. I propose the following method. Open the 

 cock E, and fill D with water ; next shut E and open C ; the 

 water in 1) will immediately descend into the syphon, and the 

 coUected air rise into D ; again, shut C, and if necessary, repeat 

 the operation, always finishing by leaving D and F full of wa- 

 ter. As the opening of both cocks at once would empty the 



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