State Agricultural Society. 441 



with slow, uncostly motion to the sea; while the products of industry, 

 charged with the value of the labor of many hands, and the busy popu- 

 lation whose time is money, glide swiftly along the ringing rail. Words 

 very imperfectly shadow out the full fruition of this new element in our 

 progress — canal navigation — compared with the illumination which 

 seems to flash upon the mind with the first ocular view of the accom- 

 plished fact. 



IRRIGATION IN PRACTICE. 



In describing the irrigation works, their two principal features — the 

 main and distributing canals — have been explained. The next step is to 

 consider the means and method for the actual application of the water 

 to the ground. The first work of the farmer is to construct his own 

 farm ditch. This lies wholly on top of the ground. The material for 

 the banks is taken from outside their line, so that the water flows wholly 

 upon the surface of the ground. The distributing canal from which the 

 water is to be taken will always be higher than the highest point of the 

 farmer's land. He will therefore be able to lay out his own ditch so 

 that the water in it shall flow on the surface of the highest land he has 

 to apply it to. The water will be discharged from the distributing canal 

 into the farm ditch by a gate which will at once measure and regulate 

 the amount of water delivered through it. To take the simplest case, 

 we will suppose the surface to be irrigated to constitute a perfect in- 

 clined plane — as it would in fact on the west side of the San Joaquin — 

 one hundred and sixty acres in extent, lying in the form of a square, 

 each side a half mile in length. Then a ditch half a mile long following 

 the western boundary of the field would serve to irrigate it. In the east 

 bank of this ditch three gates would be placed, one at each end and one 

 in the middle, distant from each other one fourth of a mile. From each 

 of these gates a furrow is run east at right angles to the ditch to the 

 opposite side of the field. As the ground slopes east at the rate of eight 

 feet to the mile, it will slope four feet in the half mile, which is the width 

 of this quarter section. And it will slope four inches in each two hun- 

 dred and twenty-four feet — say thirteen and a half rods. Twelve times 

 this distance reaches the lower side of the field. Throw up, then, with a 

 plow, twelve ridges running north and south the entire length of the field 

 two hundred and twenty-four feet apart, and each at least four inches 

 high. These may be called " checks." To irrigate this ground, open the 

 gates from the farm ditch and turn in the water. It will flow down the 

 three east furrows. Throw with the hoe a little dam across each furrow 

 two hundred and twenty-four feet east from the ditch — i. e., at the points 

 of intersection with the first "check." When the water reaches these 

 dams it will back up till it begins to overflow into the field, where it will 

 be held in the " check " till it stands four inches deep at that line, while 

 its surface will exactly intersect that of the field at the foot of the ditch 

 bank, distant two hundred and twenty-four feet west. The first belt of 

 the field next the ditch having been thus thoroughly irrigated, clear out 

 the furrow dams and hoe up three others two hundred and twenty-four 

 feet east from the first, or at the points of intersection of the furrows 

 with the second "check," repeating the operation till the field is irri- 

 gated throughout its length and breadth. In this, its simplest form, the 

 labor of irrigation is inexpensive. How often the water will need be 



56— (agri) 



