E. MINERALOGY AND GEOLOGY. 247 



marine life from Long Island Sound through the glacial pe- 

 riod and the early part of the Champlain period ; third, a 

 participation in the subsidence which affected the regions 

 farther north. For all these he presents numerous data in 

 evidence. He finds that while the glacial ice of the White 

 Mountains was not less than 5800 feet, and perhaps even 

 greater, in Southwestern Massachusetts it only extended to 

 the height of about 2600 feet above the sea. Following out 

 the more conclusive evidence, Professor Dana estimates the 

 height, at New Haven, at from 1500 to 2000 feet. This, in 

 his opinion, furnishes at the melting time material for swell- 

 ing certain waters at least to universal floods. The sink- 

 ing of the land that took place after the ice had reached its 

 height, placing the site of Montreal five hundred feet below 

 the sea-level, making Lake Champlain an arm of the great 

 St. Lawrence Gulf, and other high latitude lands much be- 

 low the present level, presents, he thinks, a sufficient reason 

 for the change of climate which began the thinning of the 

 glacier, and finally hurried on its dissolution. 4 D, Septem- 

 ber, p. 169. 



GAS WELLS OF PENNSYLVANIA. 



The opinion is daily growing more decided among those 

 who are well informed that the gases which are constantly 

 escaping from innumerable wells throughout the oil region 

 of Pennsylvania and adjacent states, represent a value but 

 little, if at all, inferior to the oil itself. The next step after 

 the realization of this fact is its utilization ; and, from occa- 

 sional paragraphs that from time to time appear, there is 

 reason to believe that the industrial employment of this ma- 

 terial, of which inestimable volumes have for years been per- 

 mitted to pass uselessly into the air, will soon become very 

 general. In a few instances the wells have been tubed, and 

 their product utilized with most satisfactory results. We 

 add herewith the following from the National Oil Journal, 

 which indicates that some progress is being made in this im- 

 portant field. The Journal remarks that the yield of the 

 few gas wells that have been tubed shows that the quan- 

 tity of the product is enormous beyond computation. A 

 gas well near Sarnersville, in the Butler oil region, flows with 

 a pressure of three hundred pounds to the square inch, and 



