214 APPENDIX. 



Example. The stroke of the valve is 5 inches, the lever for working it 10 inches, and the 

 lever for the eccentric rod 8 inches ; required the throw of the eccentric. 



Stroke 5 



8 



10)40 



4 inches throw. 



The throw of the eccentric is the distance between the circumferences of the eccentric circle 

 and the shaft, or it is the difference of their diameters. 



For calculating the proportions in any other way it will only be necessary to make the 

 throw of the eccentric and the eccentric lever, in the same proportion to each other as the 

 stroke of the valve and the valve lever. 



PUMPS. 



16. To find the number of cubic feet in the volume of a given cylinder. 



RULE. Multiply the square of the diameter in inches by half the length in inches, or 6 

 times the length in feet ; then, cutting off two figures from the right hand, divide the product 

 by 11, and the result will express the required volume in cubic feet. 



Example. What is the volume of a cylinder whose diameter is 36 inches and length 32 

 inches ? 



Diameter 36 inches 

 36 



216 

 108 



Square of diameter 1296 



Half length 16 inches 



7776 

 1296 



11) 207,36 



Volume 18'85 cubic feet. 



17. To find the power requisite to raise water to any proposed height. 



RULE. Multiply the square of the diameter of the pump, in inches, by the perpendicular 

 height of the water in feet, and by the velocity also in feet per minute, and, cutting off three 

 figures from the right hand, divide by 96. The result will express the number of horse 

 power necessary to raise the water. (274.) 



It is customary to increase the result by a -|-th part, for friction and waste. 



Example. To find the power requisite to raise a column of water 16 inches diameter, 86 

 feet high, at the velocity of 128 feet per minute. 



