PROCEEDINGS OF THE SUMMER MEETING. 59 



to export grain in large quantities, and that, too, from land which today, 

 from want of water, the reservoirs and irrigating ditches having been des- 

 troyed, is covered with the drifting sands of the desert. Today the most 

 productive sections of India and the Piedmont and Lombardy regions of 

 Europe, which are famed for their crops, owe their reputation to the fact 

 that they are provided with well arranged systems of irrigation. In our 

 own country, irrigation has been used to a limited extent for more than 

 one hundred years in many of the eastern states, where the small stream's 

 are carried along the summit of ridges and the water is allowed to trickle 

 down the hillsides. The land thus watered is generally used as a perma- 

 nent meadow or pasture, and the growth of the grass is generally more 

 than doubled. In the west, the Mormons in Utah were among the first to 

 utilize the water of the streams for purposes of irrigation. They dug 

 ditches along the base of the foot hills, and catching the waste water pre- 

 vented it from entering the streams. It was then carried in trenches and 

 used to irrigate the cultivated lands. Throughout Colorado and Califor- 

 nia, and to some extent in other western states, irrigation is regarded as 

 almost necessary for the growing of paying crops, although in some sea- 

 sons the rainfall is sufficient, without it, to give fair returns. We find 

 here many elaborate systems used for supplying water to the orchards and 

 wheatfields. Some of them have cost hundreds of thousand of dollars and 

 carry the water for fifty to one hundred miles, with the capacity to irri- 

 gate fifty thousand to one hundred thousand or more acres. In most 

 cases the water is taken from the rivers, a dam being used to raise the 

 water to the level of the bank. At other times a wing dam is used to pro- 

 ject obliquely into the stream and turn a portion of the water into the 

 irrigating ditch. To keep up the supply in the dry season, when the water 

 is most wanted, immense storage reservoirs, some of them holding enough 

 water for 50,000 acres, are often constructed back in the mountains, from 

 which the water is taken as needed. 



The main ditches, which are often twenty-five feet wide and six or eight 

 feet deep (a few measure from fifty to seventy feet wide) are carried at a 

 slope of two to three feet to the mile, and from these the distributing 

 ditches are taken off. The angle which they make with the main ditch 

 depends upon the slope of the land, as, if they descend at a greater rate 

 than eight feet to the mile, the banks will be badly washed. If a quick 

 descent is imperative the water is carried in wooden flumes or in iron pipes. 

 The bottoms of the smaller ditches are often paved or lined with cement, 

 wherever the fall is considerable or so open as to permit of rapid perco- 

 lation. When ditches of considerable length are necessary it is estimated 

 that as much as three fourths of the water is lost from evaporation and 

 percolation before it reaches the distributing ditches. 



The method used for applying the water to the land depends upon the 

 character of the crop as well as on the nature of the land and the amount 

 of water. 



HOW SHALL WE IRRIGATE ? 



In very few sections of the eastern states is it probable that irrigation 

 will become sufficiently general to admit of any concerted action, and for 

 the most part small private plants will be the rule. While we expect 

 increased attention to the distribution of the water of streams over the 

 surface of water meadows, the interest that is now being shown in the 

 subject of irrigation by horticulturists in all parts of the country warrants 



