1905 FORESTRY AND IRRIGATION 187 



State Legislature, by wise laws, has Velocity measurements were begun 

 put itself in close cooperation with the under direction of Professor Slichter 

 Reclamation Service, thereby assuring with the apparatus invented by him. 

 the fullest exploitation of its resources As the work progressed and tests were 

 by that bureau. made at greater depths it was found 

 In the matter of an investigation of necessary to modify this apparatus to 

 underground sources of supply, the suit local conditions. The various de- 

 Director of the Survey will initiate an vices used in the tests, the arrangement 

 investigation early this spring which of the instruments, the methods of 

 will be continued until complete data testing found most satisfactory, the re- 

 on this subject have been obtained. At suits obtained at each of the testing 

 the present time the department has stations, and the amount of underflow 

 very little knowledge of any areas in supposed to pass the Huron street see- 

 the State where there is sufficient un- tion are fully described by Mr. Hamlin 

 derground water to be pumped to the in his report. 



surface to reclaim public lands. As- Mr. Hamlin concludes his report 

 surance is given, however, that during with a summary of suggestions based 

 the coming season a thorough investi- on experience gained during the work 

 gation will be made with a view to as- at Huron street and in the San Fer- 

 certaining whether there are such wa- nando Valley. They are as folows : 

 ters, and the conditions under which ( : ) The ' location of the section 

 they can be obtained. where it is proposed to test the under- 

 underground Tests on i,os Angeles flow should be carefully studied. It 

 niver. should be, if possible, in a straight 

 A paper that will contribute mate- stretch of the valley, and at some dis- 

 rially to our knowledge of the impor- tance, either up or down, from large 

 tant subject of underground waters tributary streams, 

 and their use in arid regions has re- (2) The form and slope of the water 

 cently been published by the United table should be ascertained and the 

 States Geological Survey. It is a rec- line of test stations should be placed 

 ord by Mr. Homer Hamlin of under- most advantageously, 

 ground tests made in the drainage (3) In order to secure accurate re- 

 basin of Los Angeles River and il- suits, the testing stations should be 

 lustrates the conditions under which close together along the line of the 

 ground water usually occurs in arid section. 



regions and the fluctuations in the (4) The well screens should be 



water level due to rainfall and other short, and the ground should be tested 



causes. The method used in testing at intervals of 2 to 4 feet in depth, 



is of special interest. It is a method down to bed rock when possible, 



invented by Prof. Charles S. Slichter, (5) If possible, the porosity of the 



of the Reclamation Service, U. S. Geo- pervious beds should be determined, 



logical Survey, and fully described in (6) In making deep tests some form 



an earlier Survey publication entitled of drive pipe and screen, such as is 



"The Motions of Underground Wa- described in this report, should be 



ters." As the method has, up to the used. 



; present time, been used by few inves- (7) Recording ampere meter and 



tigators, the details of these tests are switch clocks should be used. The 



particularly important. discharge from a given section will 



It was in September, 1902, that Mr. undoubtedly be far less than is ex- 



i Hamlin was placed in charge of exper- pected, the popular tendency being to 



iments to determine, if possible, the greatly overestimate the amount of 



amount of underflow passing through underflow. Even if the results ob- 



the narrows of Los Angeles River at tainecl by this method of testing are 



Huron street, Los Angeles, California, not so accurate as desired, they are. 



