indicated in the table may be used specially for small 

 depths. The table gives the maximum diameter of the 

 cylinder which can be safely employed for a given depth. 

 Where an 8-inch cylinder may be employed it is false econo- 

 my (specially when land has to be irrigated) to use a 2 or 3- 

 inch pipe ; though it should be noted that a very light breeze 

 (i.e. of the velocity of 2 or 3 miles an hour) will work a 2 or 

 3-inch pump when an 8-inch pump wi'l require a 15 or 16- 

 mile breeze to work it. Local conditions, as to velocity of 

 wind at the seasons in which irrigation is needed, and the 

 depth of water at these seasons, should determine the choice 

 of the calibre of the pump-cylinder. The pump should always 

 be provided with a handle, as when the breeze is light, a little 

 coaxing with the pump-handle, results in the wheel turning 

 and continuing to turn with a comparatively gentle breeze 

 making further working of the handle unnecessary. 



152. Efficiency. A 1 2-foot mill develops 2\ horse-power 

 with average wind (i.e. wind blowing about 16 miles per hour;. 



153. Erection. The tower should be erected about 15 ft. 

 higher than surrounding trees and buildings. After the tower 

 has been erected the four anchor-posts which form the base of 

 the tower should be protected with masonry work, that the 

 tower which should be set plumb may always remain so. Even 

 rat-holes tunnelled underneath the anchor posts on one side 

 will make the tower lean on that side. 



154. Steel wind-milis constructed by Messrs. S. Freeman 

 & Sons, B. 21 Produce Exchange, New York City, U. S. A., 

 are priced thus : 



8 ft. wheel (galvanized ... 42 y 2 dollars ( x Rs, 3) 



12 ft - ( , ) ... 100 



Galvanized steel tower for 8 ft. mill. 40 ft. high ... 58^ 

 Ditto 80 ft. high ... 150 



Ditto for 12 ft. mill 40 ft. high ... 87^ 

 Ditto 80 ft. high ... 210 



