38 Reviews — Johnson & Huntley — Oil & Gas Production. 



pressure. There is no doubt that the effect of earth stresses, as 

 apart from the pressure of the overburden, will have similar results. 



Turning now to the chapter on drilling, the 103 pages devoted to 

 this subject are an extremely useful summary of the methods of 

 drilling, dealing with the matter in a way which adds interest to 

 a subject which is usually not very entertaining. The conservation 

 of oil and gas resources is another subject of striking importance. 



Vol. ii contains a description of the oil-fields of Eastern and 

 Western Canada. In Eastern Canada the more important points of 

 interest are the recently developed gas-field of New Brunswick, and 

 the possible resources in oil shales in the same province. Ontario 

 is still the chief oil and gas producer, but of recent years Alberta has 

 been coming to the fore with a rapid increase in gas production. In 

 this pi'ovince the hydrocarbons are obtained from the Cretaceous 

 Sandstone, at an horizon approximating to the Dakota sandstone. In 

 Athabaska and contiguous regions there are the extensive outcrops 

 of asphaltic sands, the so-called. " Tar Sands ", while farther north in 

 the Mackenzie River region wide untapped areas are awaiting further 

 development. 



V. C. I. 



VI. — Principles op Oil and Gas Production. By Roswell H. 



Johnson and L. G. Huntley, pp. 371. John Wiley & Sons. 



Price 1 6s. net. 

 rpHE geological aspect of the occui'rence of petroleum and natural 

 1 gas is by no means overburdened with explanatory textbooks, 

 and although the volume under discussion deals in addition with 

 other branches of the oil industry, a large proportion of its pages 

 is devoted to geological considerations. To the European student it 

 is also welcome inasmuch as it emphasizes the essentially American 

 aspect of the subject, but the widespread occurrence of natural 

 hydrocarbons in the American Palaeozoic leads the authors into 

 dangerous generalizations. Thus it produces the assertion that "it is 

 probable that a considerable production will some day be developed 

 in the older formations when they have been thoroughly prospected 

 in Europe and Asia " ; but it must be remembered that the conditions 

 of occurrence of the Palaeozoic rocks in the Central United States have 

 not their counterpart on this side of the Atlantic, although Asia may 

 produce many similarities. On the other hand, the long chapter on 

 the Oil and Gas Fields of North America is distinctly good, and the 

 chapters dealing with Oil and Gas Reservoirs and the Migration and 

 Accumulation of Oil and Gas, although necessarily short, contain the 

 germs of very suggestive ideas. 



It is a distinct relief to get away from that obsession for anticlines 

 which has of recent years somewhat obscured the vision of many 

 oil-field geologists. To such an extent has this hypothesis been 

 taken, that on several oil-fields the converse process of reasoning lias 

 been adopted and the presence of the oil been regarded as sufficient 

 proof of the occurrence of the anticline. It is by no means suggested 

 that the anticlinal occurrence of oil and gas is not of great 

 importance, but the promulgation of the idea of its exclusive 



