P limping Stations. 107 



in the boiler of 4 lb. This pressure has since been altered and 

 other improvements made. The crank shaft fiom the engine passes 

 through the wall of the engine-house, and carries a pinion gearing 

 into a spur wheel on the shaft of the scoop wheels. The ratio of the 

 velocity of the engines to the wheels is 16 to 5, and 22 to 4-|- respec- 

 tively. The larger engine — called the Holland — has a steam-jacketed 

 cylinder, 44 inches in diameter, with 8 feet stroke. The fly-wheel is 

 24 feet in diameter. The smaller engine — called the Kesteven — has 

 a steam-jacketed cylinder 45 inches in diameter and 6 feet 6 inches 

 stroke. The fly-wheel is 24 feet in diameter, making 22 revolutions 

 a minute. The framing of the scoop wheels is of cast iron. The 

 larger wheel was originally 28 feet in diameter, and fitted with forty 

 scoops, but the diameter was mcreased about ten years ago to 31 

 feet. The scoops are 6 feet 6 inches long — ^radially — ^by 5 feet wide, 

 giving an area when wholly immersed of 32 * 5 square feet. The mean 

 diameter is 24 feet 6 inches, number of revolutions a minute 5, giving 

 a gross discharge, after deducting the space occupied by the scoops, 

 of 11,215 cubic feet per minute, or 313 tons. These wheels, as run- 

 ning at the present time, have been very accurately fitted in their 

 places, and run very true, so that there is a clearance of barely half 

 an inch between the floats and the masonry at the bottom and sides. 

 The smaller wheel is 31 feet diameter, with the same number of 

 scoops, each being 5 feet 6 inches long by 5 feet wide, giving an area 

 of 27 '5 square feet. The mean diameter is 25 feet 6 inches, number 

 of revolutions a minute 4I, equal to a discharge, after deducting 

 scoops, &c., 8959 cubic feet per minute, or 250 tons. The scoops 

 dip from the radial line at an angle of 25°, being tangents to a 

 circle 7 feet 6 inches, in diameter. This angle being found too 

 small to give the best results, the end of each scoop for a length of 

 18 inches was altered so as to dip further back 6 inches. The 

 straight part of the scoops enters the water at average flood level at 

 an angle of 29°, and leaves it at ^(P, The average dip in floods 

 is 5 feet, and the average head 5 feet, rising to 7 feet in extreme 

 floods. Steam is supplied to the engines by five double-flued Lanca- 

 shire boilers, having water-pockets above the furnaces ; they are 7 

 feet diameter by 26 feet long. The total discharge of the two wheels 

 is 563 tons per minute. This is equal to about the fourth of an inch 

 of rain over the whole area of 32,000 acres when the wheels are work- 

 ing to their full capacity for twenty-four hours a day. 



The efficiency of these wheels has been gieatly increased by altera- 



