132 The Drainage of Fens and Low Lands. 



two Cornish boilers, 21 feet 6 inches long, the working pressure 

 being 13 lb. on the inch. The scoop wheel is 40 feet diameter by 

 10 feet wide, the scoops being 3 feet long. The wheel makes 4^ 

 revolutions a minute when the engine is making 25, the velocity at 

 the periphery being 9 • 42 feet per second At this pace the wheel 

 was calculated to raise 170 tons of water per minute. The water 

 approached the wheel with a velocity of 9*42 feet per second — 

 equal to that due to a fall of i • 4 feet, leaving the net calculated lift 

 8 feet. The useful effect at the trials was found to be 68*2 per 

 cent., leaving the loss from all causes, including the engine, 31-8. 

 The fuel consumed was found to be 4^ lb. per indicated horse-power 

 per hour. The total cost of the machinery for this pumping station 

 was 5000/. — equal to 2 '08/. per acre drained- Taking the greatest 

 duty at 170 tons lifted 11 feet per minute, and the total cost at 

 5000/., this gives about 40/. per horse-power of water lifted for the 

 machinery, the contract price for the wheel being 760/. The wheel 

 weighs 34| tons, and is carried by a cast-iron hollow shaft 13 inches 

 diameter, working in brass bearings 12 inches diameter by 16 inches 

 long. It has three cast-iron spoke centres 6 feet diameter; twenty 

 flat wrought-iron spokes radiated 14 feet from the periphery of the 

 centres. A ring of flat iron, 34 feet diameter, connects the ends of 

 the arms. To this ring, and a smaller one, 28 feet diameter, are 

 riveted flat-iron float spokes, bent to give the scoops the proper 

 rake. The spur wheel is 31 feet 6 J inches diameter, 10^ inches wide, 

 and 3 J inches pitch. The spur pinion, 5 feet 3 J inches in diameter, 

 is keyed on to the fly-wheel shaft, and gears into the annular 

 wheel 7 feet below its centre on the discharging side, by which 

 arrangement it was considered that the weight of the water would be 

 borne directly by the pinion. There are forty scoops, each 9 feet 

 I if inches wide by 3 feet deep, drawn tangents to a circle 13 feet 

 diameter, and formed of 3-inch Memel planks, grooved and tongued, 

 and secured by hook bolts to the float spokes. The clearance 

 between the wheel and the masonry is from \ inch to f inch. The 

 water is delivered over a crest 4 inches broad, 1 1 feet higher than 

 the bottom of the race under the wheel, and 3 feet 6 inches below 

 high-water spring tides. Water is admitted to the wheel by cast-iron 

 sluices. The channel from the wheel to 8 feet outside the inlet is 

 level, 10 feet 7 inches wide on wheel side of sluice, and ir feet 

 7 inches on outside of sluice, the sill of which is 3 inches higher than 

 the bottom of the channel. 



