200 



THE IRRIGATION AGE. 



A GOOD OUTFIT. 



The following are among the many let- 

 ters received by the Aultman-Taylor Com- 

 pany in praise of their outfits: 



DALLIS, TEX., Sept. 30, 1901. 



Gentlemen: I have been running trac- 

 tion engines and rice threshers for several 

 years in Texts and Louisiana and can say 

 the "Aultman-Taylor" outfit you sold to 

 Dr. W. W. BouHin is doing first-class work 



RICE THRESHER. 



in every particular. The engine is an easy 

 steamer and good puller on the road, and 

 the Columbia Separator is a ''hummer,'' 

 doing fast and clean work, and does not 

 crack the rice. In my opinion there is no 

 better machinery made. 



Yours truly, 



J. M. LOVE. 



RAYWOOD, TEX., Dec. 24, 1901. 

 Dear Sirs: The threshing machine pur- 

 chased of you last fall proved a fine suc- 

 cess in the rice field. We threshed at the 

 rate of one sack in 45 seconds. One of 

 the most successful rice growers said it was 

 the best job of threshing he ever had done; 

 cleaned it better and broke the rice very 

 little. The workings of the engine was 

 the admiration of the engineer. 

 Yours truly, 



C. W. CARDIFF. 



*THE MINERS' INCH. 

 A series of 235 observations was recent- 

 ly made in the hydraulic laboratory of Mc- 

 Gill university, with a view to a determi- 

 nation of "the miners' inch." The rec- 

 ords will be very useful in the mining re- 

 gions of Canada, as furnishing data for de- 

 livering water at mines. The ''miners' 

 inch" of water, it may be explained, is an 

 arbitrary measure adopted for selling water 



*From a paper read at a meeting of the Cana- 

 dian Society of Civil Engineers by T. Drum- 

 mond. 



in mining districts, and is defined as th 

 amount of water discharged by an orifice 

 one inch square (or the equivalent fraction 

 of a larger orifice), with a head of from six 

 inches to nine inches. The variation in 

 the head makes the definition rather 

 vague. In British Columbia it is defined 

 as being 1.68 cubic feet of water per min- 

 ute, or that quantity of water which will 

 pass through an orifice one-half inch wide, 

 two inches high and two inches thick, with 

 a constant head of seven inches above the 

 top of the orifice, and every additional 

 inch shall mean so much as will pass 

 through the said orifice extended horizon- 

 tally half an inch. Mr. Drummond points 

 out that, as a definition, this is completely 

 wrong. In the first place, widening the 

 orifice changes the coefficient of discharge, 

 and therefore the discharge itself. In the 

 second place, this orifice actually dis- 

 charges 2. 147 cubic feet of water per 

 minute instead of 1.68 cubic feet, and 

 this brings out a curious point, that cer- 

 tain shaped orifices with a thickness of 

 two inches run full like a short tube, the 

 vein is not contracted, and they actually 

 give a greater discharge than they are sup 

 posed to give. The shape of the orifice 

 has a perceptible effect upon the discharge. 

 Circular orifices give the least discharge, 

 rectangular orifices the greatest, and square 

 orifices are intermediate. As the rectang- 

 ular orifices become thinner, the width be- 

 ing the same, it will discharge proportion- 

 ately more water. A one-inch by two inch 

 orifice, two inches thick, is just on the 

 margin between flow with contraction and 

 full bore. If fixed in the vertical posi- 

 tion, with longest diameter vertical, the 

 vein contracts. If fixed in the horizontal 

 position, with the longest diameter hori- 

 zontal, it will also contract, but if rubbed 

 with the fingers on the edge it will run full 

 for a time and then contract again. If 

 kept running full in this way it will dis- 

 charge about one cubic foot of water per 

 minute more than when full contraction 



