136 The Drainage of Fens and Low Lands. 



and at another pumping station (Gallejon) some miles distant, a third 

 " Invincible " engine was provided, to raise 90 to 100 tons per minute. 

 The lift was low (i-o metre to i-8o metre), and experience has 

 shown that with such lifts a low efficiency was to be expected. The 

 makers, nevertheless, guaranteed that for the smaller machines the 

 steam used would not exceed -0718 kilogs. for each cubic metre of 

 water raised one metre, and that the steam per indicated horse-power 

 per hour would be from 20 to 24 lb. English. For the larger machine 

 the figures were -07 kilog. and 20 to 22 lb. English. Very carefully 

 conducted trials were made with the smaller pumps, by Mr. A. C. J. 

 Vreedenberg, a Dutch engineer, when the following results were 

 obtained from No. 2 engine, with a mean lift of i'379 metres 

 (4-52 feet) : — ^Water raised, each pump per minute, 65 • 7 tons ; horse- 

 power in water lifted, 20*18; horse-power indicated, 37*0; efficiency, 

 ' 54 J coal consumption per W.H.P. per hour, 4 * 45 lb. — 2 • 033 kilogs. 

 Owing to a slight defect in the machinery, discovered after the trial 

 of No. I engine, the results obtained were not quite as good as those 

 from the other engine; but this having been remedied, there was 

 found to be very little difference in the working of the two sets of 

 machines. Given on terms of the guarantee, the result was 

 •0627 kilog. of steam per cubic metre of water raised i metre, and 

 20 '66 lb. English per indicated horse-power per hour. The boilers 

 were of French design and construction, their evaporative efficiency 

 being not very high, 8 ' 33 lb. of water per pound of good coal. The 

 coal per indicated horse-power was 2*47 lb. This was subsequently 

 confirmed by trials of eight hours on each pump, conducted by 

 Mr. Dorn^s, engineer of the reclamation, who obtained with one 

 pump the following results : — lift 65*75 inches ; mean delivery, 64*7 

 tons; efficiency of whole machine, "579; steam per indicated horse- 

 power, 20*32 lb. ; coal per indicated horse-power, 2*44 lb. per hour; 

 coal per water horse-power, 4*21 lb. per hour. The result from the 

 other pump was practically the same. 



On the larger pump at Gallejon some interesting experiments were 

 made by French engineers with progressive speeds and lifts. The 

 lifts varied from 3I feet to 6|- feet. Three runs each of thirty minutes 

 were made with each lift^ and with a different number of revolutions 

 for each half-hour. The results showed that an efficiency of '50 was 

 obtainable on a lift of 3*28 feet; on the other lifts the average 

 efficiencies were for 4^ feet, -56; for 5 feet, '607 ; for 6 feet, '(>^\ 

 and for 6i feet, •698. All efficiencies represent, as in the experi- 



