156 The Drainage of Fens and Low Lands, 



directly connected. The lift varies from 20 inclies to 10 feet, and 

 the minimum duty of each pump was fixed by the contract at 

 500,000 cubic metres, raised to a maximum height of 3 metres in 

 23 hours, equal to about 2140 tons a minute 10 feet high. The 

 whole, including the reserve screws, can discharge 3,500,000 cubic 

 metres per day of 23 hours (about 2500 tons a mmute), and the 

 power in water raised is equal to 2000 water horse-power. The 

 engines are of the Corliss type, having cylinders 39*37 inches in 

 diameter, with 5 feet 10 J inches stroke. The body of each pump is 

 19 feet 8 inches in diameter and 12 feet high. It stands on a group 

 of six cast-iron columns, resting on the invert of the basin ; regulat- 

 ing screws are fitted to each column to adjust the level. The discs 

 or fans are 12 feet 5^ inches diameter by 4 feet 9 inches high. The 

 average speed is 33 and the maximum 36 revolutions per minute. 

 The water outlet, which springs from the annular chamber in the 

 body of the pump, is formed of two cast-iron pipes 27 feet long. 

 The inlet is trumpet-mouthed, 6 feet 10 J inches in diameter at the 

 smallest part, enlarging to 9 feet 10 inches^ with a further curved lip 

 10 feet 8 inches in diameter. Within the opening is an inverted 

 cone, which, rising in the centre, passes from a diameter of 

 11*8 inches to 23 • 6 inches. The water attains a speed of 6 feet per 

 second for the normal discharge of 6 cubic metres at 10 feet lift. 

 The lower part of the pump shaft is made hollow, to admit a support 

 solidly attached to the invert, and serving as a bearing above the 

 level of the pump itself, and nearly 5 feet above the highest probable 

 water-level. Above the disc the hollow shaft traverses a stuffing box 

 in the dome of the pump. On the top of the iron column is fixed a 

 cast-iron cylindrical head, 14* 76 inches in diameter and 17*72 inches 

 high. This head, on the upper face of which is a bearing of 

 phosphor bronze, with a concave surface, supports the whole of the 

 turning load, and also serves to centre the hollow shaft, the enlarged 

 cavity of which is at the point provided with a bronze bush 

 10 '82 inches deep. Above this bush the exterior shaft of cast iron 

 divides into two branches, meeting again above, and leaving a wide 

 opening for giving access to the pivot. The head of the hollow shaft 

 above this opening is enclosed in a plummer block bolted to a heavy- 

 girder spanning the basin. 



The quantity of coal to be consumed was limited by the terms of 

 the contract to 3*85 lb. best English coal per water horse-power per 

 hour, the quantity actually consumed being 3^ lb. The engines 



