124 MR. DAVIES GILBERT ON THE PROGRESSIVE IMPROVEMENTS 
In the certified case, 
Inches in the diameter of the lifting box 17, sq. 289 . . . Log. 2.46089/8 
Length of the column in fathoms 58 1.7634280 
Constant multiplier 2.04 0.3095101 
Weight in pounds 34185 4.5338359 
Length of lifts 6 feet x 5£ the number in a minute = 33, 
33 multiplied by 1440 = 47520, and this number 
X by 61 = 2’898720 6.4622063 
Pounds into feet during the whole period of 61 days 
99092’800000 10.9960422 
Bushels of coal consumed in the 61 days 14.080 4.1486027 
The duty 7’037800 6.8474395 
If the quantity of water lifted at each stroke is required in imperial gallons ; 
square as before the diameter of the lifting box or plunger in inches, multiply 
by the length of the stroke in feet, and by 0.034 (the fractional part of an im- 
perial gallon in a cylinder one inch in diameter and a foot long — the loga- 
rithm 8.5313588) : the product will be the gallons raised. 
Diameter in inches squared as before Log. 2.4608978 
6 feet 0.7781513 
Constant multiplier 0.034 8.5313588 
Number of gallons 58.94 1.7704079 
5 £ strokes in a minute, X minutesin61 days 87’840 = 483.120 5.6840550 
Imperial gallons in 61 days = 28’475000 7-4544629 
Eacli separate engine on the new construction underwent a constant com- 
parison, during the whole time of its continuing in action, with the duty of the 
two standard atmospheric engines as reported by the committee. 
The diameter of the various lifting boxes or plungers, the length of the lifts 
or columns of water, and the lengths of the strokes, were matters of common 
notoriety ; and the number of times moved by each engine in a given period 
was ascertained by a contrivance denominated a Counter, placed on the great 
beam ; this apparatus involves a series of wheels and pinions set in motion by 
