17 



EXTERNAL TANK. 



There is in the centre of the Front 

 Court Yard, 50 ft. from the Principal 

 Entrance Gates facie g Great Russell 

 Street, an underground tank, about 18 

 inches below the level of the ground, 

 which is kept full. The water is 

 always on, and the supply is regulated 

 by means of a Stop Cock, the opening 

 of which will cause sufficient water to 

 run in to keep the tank constantly 

 full, even when several Engines are 

 pumping from it together. 



EXTERNAL IRON MAIN. 



An Iron Main of 9 inches in- 

 ternal diameter lies round the out- 

 side of the Main Building, and also 

 round the outside of the interior 

 Quadrangle. It is about 3 ft. under 

 the surface of the ground, and is 

 kept always full of water by the New 

 River Company. This main has 

 connected with it one chief command 

 cock, two supply cocks to roof, one 

 safety valve, seven divisional cocks, 

 and 34 Fire Cocks, numbered con- 

 secutively from 98 to 146 both inclusive. 

 It has also a pressure gauge, which is 

 placed in the Firemen's Room. 



There is on the roof an Iron Main 

 of three inches internal diameter, ex- 

 tending along the whole length of the 

 four sides of the Quadrangle, round 

 the Dome, and along the roof over 

 the Elgin Gallery. 



This main has connected with it six 

 stationary Engines which pump the 

 / 84520. B 



