90 IRRIGATION. 



into distributing canals, c, c, c, which carry the water 

 within a few feet of each tree. (The position of the 

 trees in the figure is indicated by the dots. ) Here a sharp 

 bar is trust into the ground in several places, penetrating 

 in different directions toward the roots, and leaving holes 

 by which the water soaks into the earth and reaches the 

 roots. The second is a more elaborate but a more prefer- 

 able method. The water is led from the canals into 

 circular furrows which curve so as to embrace the tree. 

 (This is shown at d,e, in fig. 38.) These furrows are 

 broad and shallow, and the water overflows from them in 

 a thin sheet or a multitude of little rills which lead to 



v^ 



a a 



Fig. 39. FORMATION OF FURROWS. 



the lower side of the tree, where they are arrested by 

 means of a slight embankment raised with the hoe. In 

 this case the water is brought exactly where it is needed, 

 and every rootlet is supplied. This is also seen at fig. 39. 

 In irrigating vines very similar methods are adopted. 

 As the vines are planted in rows, the distributing furrows 

 are carried down the center of each alternate row, fig. 40, 

 the ground being sloped towards the center of each in- 

 termediate row, fig. 41. The water is thus made to pass 

 across each row of vines. Beneath the center of the in- 

 termediate rows a tile drain should be placed to carry off 

 surplus water, and this brings into notice the question of 

 drainage as a part of this system of orchard and vineyard 



