278 SCIENCE IN SHORT CHAPTERS. 



As the oil industry of America is of such great national 

 importance, an investigation of this kind is worthy of the 

 energies of the American Government geologists. It would 

 throw much light on the whole subject, and supply data 

 from which the probable duration of the oil supply might 

 be approximately calculated. 



Such an investigation might even do more than this. By 

 proving the geological conditions upon which depend the 

 production of petroleum springs, new sources may be dis- 

 covered, just as new coal-seams have been discovered, in 

 accordance with geological prediction, or as the practical 

 discovery of the Austrian gold-fields was so long preceded 

 by Sir Roderick Murchison's theoretical announcement of 

 their probable existence. 



When the "kerosene wells" were first struck, the specu- 

 lations concerning their probable permanency were wild and 

 various. Some maintained that it was but a spurt, a freak 

 of nature limited to a narrow locality, and would soon be 

 over ; others asserted forthwith that American oil, like 

 everything else American, was boundless. Neither had any 

 grounds for their assertions, and therefore made them with 

 the usual boldness of mere dogmatism. 



Then came a period of scare, started by the fact that 

 w\3lls which at first spouted an inflammable mixture of oil 

 and vapor high into the air soon became quiescent, and 

 from "spouting wells" became "flowing wells," merely 

 pouring out on the surface a small stream at first, which 

 gradually declined to a dribble, and finally ceased to flow at 

 all. Even those that started modestly as flowing wells did 

 the latter, and thus appeared to become exhausted. 



This exhaustion, however, was only apparent, as was 

 proved by the application of pumps, which drew up from 

 wells, that had ceased either to spout or flow, large and 

 apparently undiminishing quantities of crude oil. 



Further observation and thought revealed the cause of 

 these changes. It became understood that the spouting was 

 due to the tapping of a rock-cavity containing oil of such 

 varying densities and volatility that some of it flew out as a 

 vapor, or boiled at the mean temperature of the air of the 

 country or that of the surrounding rocks. Such being the 



