water into it from cisterns underneath 

 the roof, and these cisterns are in 

 their turn supplied by rising mains 

 connected with the external under- 

 ground pipe, and by that means also 

 connected with the New "River Com- 

 pany's Works. Although the water of 

 the New River Company is always on 

 sufficiently to keep the outside under- 

 ground tank and pipes charged, the 

 pressure is not at all times sufficient 

 to drive the water into the cisterns 

 underneath the roof, At some period, 

 however, during every twenty-four 

 hours the pressure is on for a sufficient 

 time to fill all these cisterns which 

 may require water, the supply being 

 regulated by ball-cocks ; so that in all 

 ordinary circumstances they may be 

 calculated on as containing a full 

 supply of water up to the level at 

 which the balls close the cocks. 



In addition to the six stationary 

 Engines already mentioned, this main 

 has connected with it 34 Fire Cocks 

 and 9 Divisional Cocks, the whole 

 being numbered consecutively from 

 53 to 97, both inclusive. All these 

 Stop Cocks, except the Cock marked 

 52 on S.W. Staircase, are ordinarily 

 kept open ; but any oue or more of 

 them can be shut in case of need, so 

 that, if required, the whole of the 

 Engines can be worked together 

 through one or more Fire Cocks. 



The Hose pipes, the branches or 

 directing pipes and other necessary 

 appliances for this main, are kept on 

 the roof in boxes, which stand close 

 by the Engines. 



