30 CONSTRUCTION OF AN HYDRAULIC APPARATUS, 



If the lower end of the pipe B C was inferted into the lower 

 fide of the veflel A, the water might be forced out of this 

 velfel into the higher, by admitting the preflure of the atmof- 

 phere. The higher water pipe however, fhould defcend 

 confiderably below the bottom of the veflel, and its valve 

 fhould be always kept in good order, or part of the raifed 

 water will be drawn down again when the air in the lower 

 veflel is rarefied. Indeed if we can infure the tightriefs of the 

 valves, water may be carried through any number of veffels, 

 without being delivered into any ciftcrn before the requifite 

 height is obtained. 

 Conftru&ion of The apparatus reprefented in PI. III. may be ufed to raife 

 raifing water water below the refervoir, if the veflels and their, water pipes 

 below the refer- are fufficiently fettled, and the air pipe 1 placed in a vertical 

 pofition ; but for this purpofe the combination reprefented in 

 PI. IV. will be preferable. It is an inverflon of the former 

 method. A ftream of water falls down the pipe L, pafles 

 through the veflel V, and afcends again through the fhorter 

 pipe S. When there is a fufheiency of water to fill the longer 

 pipe, the ftream flows through the apparatus with confider- 

 able celerity. The longer pipe L having feveral fmall holes at 

 the turn near the higher end, a quantity of air is drawn into 

 the ftream, and defcends into the veflel Y, where it quits the 

 current, rifes to the higher part of the veflel, and deprefles an 

 equal bulk of water, which is carried through the pipe S- 

 „ This explains the principle. 



The air however is not fuifered to collect in the veflel V, 

 but is conveyed through the pipe 1, into one of the veflels 

 A B, previoufly rilled with water, which it forces into the 

 ltream. The alternate connection of 1, 2, and 1,3, is com- 

 pleted by a cock of the fame conftruclion, as is defcribed in 

 the explanation of PL III. and by the fame kind of machinery # 

 The lower parts of the apparatus, PL IV. to above the 

 veflels A B, arc immerfed in water. At prefent the veflel V 

 communicates with the veflel A ; the water will accordingly 

 defcend out of A through the tube below 2, which has a valve 

 opening downwards. A fmall conical valve at the lower end 

 of a pipe inferted into the top of B, being opened immediately 

 before the communication between V and A is completed, 

 the condenfed air nifties out of B, and water enters through an 

 aperture under that letter, while the valve under 3 is clofed, 

 4 When 



