WATER SUPPLY AND PUMPS 



On the other hand, steel tanks are excellent If 

 they have round or concave bottoms, but they 

 are difficult to keep painted, and the overflow 

 and supply pipes have to be carefully protected 

 against frost. Concrete tanks are expensive, 

 and there are none better, but in them also the 

 supply and overflow pipes must be protected in 

 winter. 



Concrete reservoirs are well worth the ex- 

 pense if they can be built on a hill, so that the 

 bottom of the reservoir is higher than the roof 

 of the highest building. In planning a reser- 

 voir, if It is borne in mind that a gallon Is 

 equivalent to 268.8 cubic inches, it will be an 

 easy matter to figure the required dimensions. 

 If it is found advantageous to build a reservoir 

 it should be large enough to contain a week's 

 supply; and, furthermore, it should be covered, 

 in order to exclude the sunlight, which causes 

 the growth of vegetable matter In the water. 



Attic tanks never prove very satisfactory, as 



in case of fire there is not sufficient force to 



throw water over the roof. Moreover, large 



tanks require strong supports, and frequently 



17 



