Ptmtping Stations. 1 5 ^ 



57-46 tons per minute. The horse-power of the engine in water 

 lifted was 24 water horse power. The consumption of coal was 

 at the rate of 2 1 • 34 lb. per water horse-power per hour. 



There are now two pairs of pumping stations, each having in- 

 stallations consisting of scoop wheels and centrifugal pumps. The 

 scoop wheels at present in use are the largest in diameter in use 

 in Holland, one being for the lower lift and the other for raising 

 the water from the Ringvart to the collecting basin. The wheels 

 are 32*80 feet in diameter and 4 feet wide. The lift is 11*80 feet 

 for the lower, and 8* 20 feet for the upper wheel. They have thirty- 

 two curved iron scoops, the curve being concave to the internal 

 water, and make 4^ revolutions a minute. The velocity at the peri- 

 phery is 7*22 feet per second; the weight of one wheel with its axle 

 is 21 tons. The author has seen these wheels at work, his impres- 

 sion being that their performance is not satisfactory, the scoops 

 not entering or leaving quietly, or with the best effect, the water 

 being too much dashed about. The wheels are not provided 

 with shuttles to regulate the supply of water to the scoops. These 

 wheels work in an uncovered masonry raceway outside the engine- 

 house, and are driven by single-cylinder condensing horizontal 

 engines. The wheels discharge 110*5 tons per minute to a height 

 of 11*75 feet; the horse-power of the engines in water lifted is 

 eighty-nine, and the consumption of coal at the rate of 7 lb. per 

 water horse-power per houn The two steam engines and wheels 

 cost 5000/., or at the rate of 28*03/. per water horse-power. 



The centrifugal pumps were erected in 1876 by Messrs. Gwynne and 

 Co., London. They are of the direct-acting type, having horizontal 

 spindles, and are fixed in pairs in the two engine-houses, one for the 

 lower and the other for the upper levels. The suction and delivery 

 pipes are 3 feet in diameter, and the latter is carried by a bend 

 below the lowest water-level in the basin into which it discharges. 

 Each station has two pumps driven by separate non-compound direct- 

 acting engines, fitted with variable expansion gear, and having steam- 

 jacketed cyhnders, 24 inches diameter, with 20 inches stroke ; the 

 engines and pumps making 100 strokes per minute at the full lift of 

 13 feet. A separate air pump is provided for charging the pumps at 

 starting. Each pump is capable of raising 7 1 tons per minute. The 

 diameter of the pump disc is 6 feet, and the width 3 feet. Steam is 

 supplied by four Lancashire boilers, with 24 Galloway tubes 25 feet 

 long by 6' 5 feet wide, at the lower station; and three boilers at the 



