Velocity of wind. 



Popular Description Equivalent in miles Equivalent in Force exert- 



per hour. feet per second, ed per square 



foot of sail. 



N.B. By 'average wind' is to be understood wind blowing at the rate of 

 15 to 16 miles an hour. 



Discharge of water by pump. 



Diameter of pump- Weight of water con- Amount of water dis- 



cylinder. tained in ift length of charged by every inch 



inch 



3 



3# n 



4 



5 8-575 -0850 



