REVIEWS. 



70 



For our part we are inclined to join issue with Mr. Hull, on some points — 

 two in particular. First, we think he has underated the annual drain upon our 

 coal-store : and, consequently, the supply he calculates upon will not last a 

 thousand years. Moreover, we think the exhaustion will be accelerated by a 

 much larger increased demand than the three millions of tons he allows. But 

 then on the other hand we do not think he has admitted all the available 

 store we possess. He has restricted mining-operations within a depth of four 

 thousand feet, on account of the increase of temperature — regarded, generally, 

 by geologists as equal to one degree of Fahrenheit for every sixty feet — and 

 that greater depths present insurmountable difficulties for engineering operations. 

 Doubtless, in one sense this is a right way to view the question, because as increased 

 depth causes proportionally increased expenses, and greater cost of the material 

 the more we should be placed at a disadvantage with respect to other nations 

 whose coal-fields might be more accessible. When needs must, however, our en- 

 gineers will undoubtedly surmount both the difficulties of mining, and find also 

 some plan for keeping the mine cool enough for the workmen. We must also 

 bear in mind that if the temperature increase with the depth, it does so in an 

 ever decreasing ratio ; and that from one degree to fifty feet from the surface, 

 we have at greater depths to go seventy-five or eighty feet for an equivalent 

 increase. 



Our space, however, will not allow us to discuss these questions at length. 

 Mr. Hull's book opens out a very important subject for consideration, and will, 

 we trust, draw a wider attention from the public, and more detailed information 

 from the School of Mines. Some important data have already been printed by 

 Mr. Robt. Hunt, in his Mineral Statistics ; and we hope to see these extended, 

 and the whole subject grappled with in a manner worthy of a national institution. 



Mr. Hull's book deserves attentive reading; and being inexpensive, that 

 result ought to be attained. 



On the Primordial Fauna and the Taconic System. By Joachim Barhande ; 

 with additional Notes, by Jules Marcotj. Boston, U. S. : 1860. 



One great value of scientific research is the kinship it makes between peoples 

 who would else know little of each other, and without it have no inducement 

 to become better acquainted. Commerce is said — and very truly, too — to 

 make communion between man and man, though a geographical division of a 

 thousand leagues may part them ; but the deep thinking men of any nation, if 

 this was the only " free passport," would be shut out from participation in the 

 great and varied benefits accruing from an extended intercourse. For they, 

 whom " men of business" usually look upon as " half witted," and as men be- 

 hind the age — " busying themselves about things unprofitable, and past finding 

 out" — have no stake in the wide-cast net which is fast covering the earth, and 

 drawing its riches into certain vortices of trade, to the impoverishment of 

 the many and the enrichment of the few. So that unless rock unto rock 

 answered as truly as American cotton does to English gold, or African ivory 

 to Birmingham guns, the value of the highest scientific researches a man could 

 engage in would be lost in its best and noblest sense, from being locked up 

 within the brain that imagined it, or exported wildly, without hopes of an im- 

 ported return corresponding to it in value. Science which conduces to com- 

 merce, being made subservient to the lower purposes of trade, will always be 

 cosmopolitan in its extension, and be well thought of everywhere ; but it is of 

 theoretical geology we are now writing, and this, because it cannot be made 

 to agree with any standard of human weight or measurement, commerce will 

 have naught to say to. But here do not let us be misunderstood. We have 



