PEALE.] 



DESCRIPTIVE GEOLOGY SODA SPRINGS, &C. 



595 



* In the sun. 



The thermometers used in 1871 were ordinary thermometers, while 

 those used in 1877 were made especially for taking the temperatures of 

 springs. The table just given shows that very few of the springs can be 

 classed as thermal, few if any, except the Steamboat spring, exceeding 

 the temperature of the air. Observations should be made in the winter,, 

 however, to determine whether the temperatures exceed the mean an- 

 nual temperature. Some of the springs exposed to the direct rays of 

 the sun are evidently raised in temperature. 



One cannot help being reminded as he wanders among the extinct 

 spring-basins that they are dying out, and long ago must have been 

 wonderful in their dimensions and x)henomena. As Dr. Hayden has 

 said, "At this time they may be called simply remnants of former 

 greatness." 



The formation of the cones is similar to what is seen in the cones of 

 }iot springs, viz, the overlapping of successive layers. It is, therefore, 

 exceedingly probable that these springs were once all boiling or at least 

 hot springs. 



A few miles east of the village of Soda Springs at the mouth of a 

 small canon there is a collection of sulphur springs and a pool or lake, 

 the surface of which is agitated by the escape of carbonic acid gas and 

 sulphuretted hydrogen, which fills the surroundiag atmosphere. The 



