\ 



196 EXPERIMENT STATION RECORD. 



thero is no certainty as in tlic ilc])th at which it will he I'nuinl or the thickness of the 

 stratiun. . . . 



"Thruughuut tlie whule length of the valley proper water will be found at adejjth 

 of from 4 or 5 ft. to 20 or 30 ft., depending upon the height of the ground above the 

 level of the river bed. This water appears to be generally of a good and fairly uni- 

 form quality throughout the valley, though near to the foothill.s tlie quality is an 

 vmcertain thing. In the matter of quantity it seems to be more a matter of provid- 

 ing means for making the water available than any question as to the underflow." 



The open well is considered in most resi>ects preferable to the pipe, but under 

 present conditions is too expensive. 



^lethods of sinking wells, installing pumps and strainers, and operating pumps are 

 exijlained. The results of comparative tests of 8 pumps of various types (centrifugal 

 and rotary) and sizes and of 4 kinds of fuel (cotton wood, tornillo, and coal) are 

 reported. Data regarding pumping plants in New Mexico and other States are given. 



Summarizing the results of studies and observations, the authors state that — 



"An ample quantity of water for irrigating purposes exists throughout the Rio 

 Grande Valley in southern New Mexico at a comparative shallow deptli. 



"This water, termed the underflow, can be easily made available by sinking jtipe 

 wells, with slotted strainers, into the gravel strata at comparatively low cost. 



"The station at Mesilla Park sank an experimental well ii in. in diameter and 48 

 ft. deep from -which w'as pumped a continuous stream of over 1,000 gals, a minute. 



"From this well it was found possil)le, using a 20-horsepower steam engine with 

 tornillo wood as fuel, to irrigate average land 3 in. deep at a maximum cost of from 51 

 cts. to 64 cts. an acre, according to the pumj) used. This estimate is for short runs; 

 for long runs this cost will probably be reduced, ar point to be determined later. . . . 



"A study of the relative conditions existing in New Mexico and other States shows 

 that in the Rio Grande Valley in southern New Mexico at least the conditions are 

 unusually favorable for the successful and economical operation of pumping plants 

 as a means of supplying water for irrigating purposes." 



Contributions to tlie study of drainage and irrigation, E. Risler and G. 

 "Weky {Ann. Inst. Nat. Agron., 2. ser., 2 {1903), No. 1, pp. 5-18). — This article dis- 

 cusses the consumption of water by plants and the relation between the distribution 

 of rainfall in different parts of France and the water requirements of plants. 



Discharge of the principal rivers of Montana, J. S. Baker {Montana Stu. Ept. 

 1902, pp. 117-1.-! 1). — A tabular record of stream measurements made in cooperation 

 with the U. S. Geological Survey. 



The resistance of road vehicles to traction, A. Bixxie et al. {Rpt. BrUi^h 

 Assoc. Adv. Sci., 1902, pp. 314-349, ph. 4, fifjs. 4). — This is the report of the com- 

 mittee appointed to consider this subject. It reviews the investigations of Correze 

 and Manes (1832), Coriolis (1835), Morin (1837-1842), Dupuit, Edmund Leahy 

 (1847), Charie-Marsaines, A. Michelin (1896), \V. C. Unwin (1897), H. S. Hele- 

 Shaw (1897), and I. 0. Baker (1902), and describes the apparatus and methods used 

 and results obtained in some tests made by the committee. 



The experiments undertaken were intended "to determine the relation between 

 the tractive effort and the following, viz, load, diameter of wheel, width and section 

 of tire, hardness of tire (in the case of pneumatics), effect of springs, and velocity for 

 every type of road under all circumstances, and any other relations that may Ije sug- 

 gested during the progress of the work." 



The special dynamometer apparatus used in the tests is described in detail. It 

 consists of a castor frame in which can be mounted the wheel to be experimented 

 on, a system of levers for transmitting to a small plunger the pull exerted on the 

 wheel, and a recording pressure-gauge for registering the same, together with a record- 

 ing tachometer. 



"In performing an experiment a given type of wheel is mounted in the frame and 

 a run made over a piece of road of the desired type. Since the 2 graphs are side 



