32 



IRRIGATION. 



structed in the shape of arms shorter or longer, accord- 

 ing to the power needed fixed to a center-wheel or hub, 

 which is mounted and keyed on to an axle. Sails are 

 carried on these arms, of sail-cloth or heavy sheeting, of 



a triangular shape, 

 as shown in the en- 

 graving, which are 

 fastened closely to 

 one arm and by a 

 cord in the corner, 

 shown at a, a foot 

 or less in length, to 

 another. This gives 

 sufficient inclina- 

 tion backward to the 

 sails to gain the mo- 

 tion required with a 

 front wind. On the 

 axle is a crank- 

 wheel, I, which 

 moves the rod to be 

 connected with the 

 pump, or it may be 

 connected by means 

 of pulleys and bands 

 to get an upright 

 rotary motion, or a 



Fig. 1. WINDMILL WITH SAILS. -i i , -, 



pair of bevel-wheels 



will give a horizontal rotary movement. A frame, c, is 

 carried on a circular table, on which it may be revolved 

 so as to enable the sails to be presented fairly to the 

 breeze ; a box, d, at the rear end of the frame is weighted 

 with stone, to balance the weight of the arms and sails. 

 A pin passed through holes in the circular table retains 

 the frame to the position needed, and keeps the sails 

 faced to the wind. 



