448 GEOLOGY OP NORTHWESTERN TEXAS. 



bottoms of the evaporating pans, and they must be scaled occasionally, for 

 this coating is a non-conductor of heat, and so much fuel is wasted in keep- 

 ing up the amount of heat necessary that it is found economical to take up 

 the pans and by an expensive process take the scale off. A good deal of the 

 gypsum may be gotten rid of by heating the brine before it goes into the 

 evaporating pans. 



The chlorides of calcium and magnesium do not precipitate as readily as 

 the common salt, and remain in the water left in the pans after all the salt 

 has been precipitated. The only ill effect of the continued boiling of the 

 water with these ingredients is that there is more or less hydrochloric acid 

 turned loose, which attacks the iron of the pans and causes them to rust. 

 The presence of chloride of magnesia in common salt is not an objectionable 

 feature in a southern climate, where it is desirable in preserving meats that 

 the salt should dissolve as soon and rapidly as possible. 



From the analysis of the water at Colorado City, as given elsewhere, it will 

 be seen that there is a very small percentage of gypsum in that water, and a 

 part of that will be lost by evaporation, so if the whole remaining salts be 

 precipitated it will yet be a first-class material. 



The Texas Salt Company, of which Mr. George E. Briggs is president, are 

 at Colorado, Texas. Their works are situated two miles east of that place 

 on a high plateau overlooking that town. They get their water from four 

 wells of about one thousand feet depth. The water is pumped from these 

 wells by windmills thirty feet in diameter. In sinking these wells at a depth 

 of about eight hundred and fifty feet a bed of rock salt was reached, and 

 within the next two hundred and fifty feet one hundred and forty feet of 

 rock salt was passed through. 



The water in the wells rises to within about one hundred and fifty feet of 

 the surface, and it has been found impossible to exhaust the supply of water 

 in any of them by pumping. There has been no change in the character of 

 the water since the company first began operations. The wells are cased to 

 the depth of eight hundred and fifty feet, or to the first bed of rock salt. 

 Fresh water was found in the wells both above and below the beds of salt. 

 This company manufacture the salt by solar and steam evaporation, and pro- 

 duce seven hundred and fifty tons per month. This salt is sold in various 

 parts of the State. 



The following is an analysis of the water from these wells made by Mr. L. 

 E. Magnenat, Chemist for the Survey: 



