112 TOWERS AND TANK'S FOR WATER-WORKS. 



Capacity in gallons = X f j.4&=i.Q,6D 2 A l . 



Capacity in pounds = 1 X625 = i6. 



Capacity of Segment of a Sphere. 



Capacity in cubic feet = %7rR 2 3 (2 3 cos w+cos 3 w), 



or 

 Capacity in gallons = j.&4R 2 3 (2 3 cos ^+ cos 3 w), 



or 7 .8 4 ^ 2 2 (3^ 2 -^ 2 ). 

 Capacity in pounds =6$.$R 2 3 (2 3 cos at + cos* <D), 



or 



Capacity of Hemisphere. The hemisphere may be considered 

 a special' case of the segment of a sphere in which A 2 = R 2 = 



D 



, and a> = 90; then 



nD* 



Capacity in cubic feet = - - = o.262Z> 3 . 



Capacity in gallons = i.g6D 3 . 

 Capacity in pounds = i6.36D 3 . 



Areas 0} Surfaces. The areas of the surfaces are needed for 

 computing the weight of metal in the shell. They are: 



Cylinder. .. .area in square feet =nDA. 

 Cone ...... area in square feet =%xDA l sec 0. 



/D 2 \ 

 Segment. . . .area in square feet *l --- M 2 2 K o r 



Hemisphere, area in square feet = jTrD 2 . 



Stresses 'in the Cylinder. The stress on a horizontal joint of 

 a vertical cylinder, or on the section made by a horizontal plane, 



