SALT INDUSTRY. 235 



north to south, beyond which the surface of the desert has a gentle incHna- 

 tion eastward. The surface of the lake-beds when first deposited was hori- 

 zontal, and the present inclination is due to a fault crossing the valley with 

 a north and south strike, and to the tilting of the orographic block on which 

 the eastern portion of the valley is situated. The tilting of the floor of the 

 valley resulted in the establishment of a drainage to the eastward for the 

 surface waters, and the formation of a small lake at the eastern end of the 

 valley near Sand Springs. During the winter the water collects there, foi'm- 

 ing a sheet of brine of variable size, sometimes covering 10 or 15 square 

 miles of surface, but with a depth of only a few inches. In the summer 

 the water evaporates and adds to the layers of salt previously deposited. 



The deposit of salt thus accumulated is from 3 to 5 inches thick near 

 the margins, and is said to have a depth in the central portion of the basin 

 of not less than 3 feet. It is gathered by simply shoveling it into barrows 

 and wheeling it out on to firm ground, where it is piled in huge heaps ready 

 for transportation. 



The surface of the inclined lake-beds draining to the salt fields is abso- 

 lutely destitute of vegetation, and usually exhibits no saline efflorescence, 

 since this is dissolved away to supply the salt field. The soil, like that be- 

 neath the accumulated salt, is a fine, greenish, saline clay, and may be 

 readily examined in the sides of drainage channels, which score the sloping 

 surface to the depth of 3 or 4 feet. 



The method here arranged by nature for dissolving the efflorescent 

 salts from the surface of the lake-beds and evaporating the saline waters in 

 the restricted basin is practically the same as that employed by man on a 

 smaller scale at the Eagle and Desert Crystal Works. 



Associated with the salt obtained at the various salt works are greater 

 or less quantities of the borate of soda and the borate of lime, and in some 

 cases, as at the borax works in Alkali Valley, they attain such importance 

 as to afford a considerable quantity of borax There are many other local- 

 ities in the Lahontan Basin where the chloride, the borate, the sulphate, 

 and the carbonate of soda exist, sometimes in large quantities, in the in- 

 crustations that form on the deserts, but at present the demand is not suffi- 

 cient to warrant the working of these deposits for economic purposes. 



