THE IRRIGATION AGE. 



the top of stake E ; while the dotted line C represents 

 the top of the water, and the distance between the 

 lines gives the true depth or spill over the weir board. 

 The line D has the appearance of running over the top 

 of the board; when in fact it passes behind it the 

 reader is supposed to look through the board and the 

 post. The surface of water after passing below the 

 board, should not be nearer the notch B than ten 

 inches. Neither should the nature of the channel 

 above the board, be such as to force or hurry the 

 water to the board ; but should be amply wide and 

 deep, to allow the water to approach the notch 

 quietly. If it passes the channel rapidly, it will be 

 forced over the notch and a larger quantity will pass, 

 than the table indicates. 



The weir table herewith gives the number of cubic 

 feet of water passing per minute, over the notch for 

 each inch in breadth. The figures 1,2, 3, etc., in the 

 first vertical column, are the inches depth of water 

 over the weir; the first or top horizontal line is frac- 

 tional parts of an inch. The body of the table shows 

 the cubic feet, that will pass each minute, for each 

 inch depth of weir, from 1 to 25 inches. Each of 

 these results is for one inch in width ; for any particu- 

 lar number of inches width of weir, the result obtain- 

 ed in table, must be multiplied by the number of 

 inches of breadth the weir may be. Suppose the 

 notch in the board is twenty inches wide; and the 

 water at the stake E, 5^ inches deep; in the first 

 column find the figure 5. Follow the horizontal line 

 of figures until a vertical column is reached contain- 

 ing J^ fraction at the top. The square where these 

 two columns meet will contain 5.18 (five and eigh- 

 teen-hundredths) cubic feet. This is the quantity 

 of water passing for each inch in width; since the 

 supposed weir is twenty inches, this result must be 

 multiplied by 20, which gives 103.6 (one hundred and 

 three and six-tenths) cubic feet per minute. In this 

 manner the water passing any width of weir, of 

 any depth from 1 to 25 inches, can be easily cal- 

 culated. 



WEIR TABLE 1 TO 25 INCHES 



WINTER IRRIGATION OF ORCHARDS. 



BY F. C. BARKER, OF LAS CRUSES, NEW MEXICO. 



AT the request of the editors I will briefly sub- 

 mit the results of my observations on the 

 question of the winter irrigation of orchards 

 in this part of the country, and the conclusions 

 which, it appears to me, we may draw both from 

 practical experience and scientific knowledge, for 

 the consideration of readers of THE IRRIGATION 

 AGE. 



When, some four years ago, I came out to New 

 Mexico, I found that the prevailing practice with 

 prchardists was to withhold water from the trees dur- 

 ing September and October, in order to let the young 

 wood ripen; then give one irrigation in November 

 and not apply water again until the peach buds had 

 come into blossom. The reasons alleged for this 

 method of treatment were, that the trees did not 

 need water during the winter months, when they 

 were dormant, and that by keeping off the water the 

 fruit buds were retarded. It is needless to say that 



no objection can be raised against withholding the 

 water while the young wood is ripening: but that by 

 beeping the water from the trees in the spring the 

 blossoms are thereby held back has been shown to 

 be a fallacious idea. The fact is that the bursting of 

 the bud is entirely dependent upon the state of the 

 outside and surrounding atmosphere, and if the 

 application of water to the roots has any effect what- 

 ever upon the buds, the evidence is in favor of the 

 retarding rather than of hastening the blossoming 

 period. It would appear that the mistaken notion 

 about trees needing no artificial irrigation during 

 winter has arisen from two sources. Firstly, there is 

 a popular delusion that the tree is dormant during 

 winter. Anyone, however, who has heeled in young 

 trees in the fall and lifted them again in the spring, 

 cannot have failed to notice that the roots have made 

 growth during the interval, and, by careful measure- 

 ments made at the Experiment Station here, it has 



