Notices respecting New Books. 323 



and publication of these papers. Since he (ten years ago) first 

 propounded in these pages the central idea of his theory to account 

 for the then mysterious phenomena of the glacial drift, he has gone 

 on patiently and successfully, not only buttressing his position by 

 additional facts, arguments, and illustrations, but also enlarging 

 its scope and widening its sweep till it has attained the solidity 

 aud dimensions presented in the present work. The publication 

 of this volume marks one of the great eras in the progress of 

 geological investigation. It is only necessary to compare a manual 

 of physical geology of fifteen years ago with what the same ought 

 to contain at the present day, to see how enormous is the modifica- 

 tion made in fundamental principles, what a number of crude ten- 

 tative speculations have given place to solid well-compacted theory, 

 and how many loose and helpless -looking facts have by such theory 

 found their fitting place and explanation. And when it is asked 

 to whom science is chiefly indebted for this extension of its borders, 

 who has made the most powerful and lasting impress on modern 

 geological speculation, the answer undoubtedly should be — Mr. 

 James Croll. No greater clearing of ground, lengthening of cords, 

 and strengthening of stakes in the fields of geology have taken 

 place since the days of Hutton ; and while the Scotch may honour 

 their Lyell, Murchison, Ramsay, and Ceikie, they have the highest 

 reason to be proud of their Hutton and Croll. 



The manner in which Mr. Croll meets and combats Dr. Car- 

 penter's theory of oceanic circulation is very characteristic of the 

 unwearying patience, acuteness, and courage of his investigations. 

 It is not our purpose here to express any opinion on this unfinished 

 controversy, further than to say that Mr. Croll follows Dr. Car- 

 penter into every one of his positions with a resolution and tenacity 

 of purpose which, were it not so really calm and passionless, might 

 almost be looked on as cruel and unmerciful. When, according to 

 his own view, he has completely overthrown any of Dr. Carpenter's 

 arguments by one special line of attack, he opens fire upon it from 

 another point with the same hearty goodwill he might be expected 

 to exhibit in leading a gallant onslaught against any hitherto un- 

 assailed position. This he does not do with the intention of thrice 

 slaying the slain, but simply because he has in an eminent degree 

 the faculty of examining a problem from many sides ; and he is 

 concerned, not for dialectic triumphs, but for the presentation of 

 truth in its entirety. No sooner has the active and versatile Doctor 

 marshalled new arguments from new facts in favour of his vast 

 conception, than Mr. Croll is ready to take up his challenge, and 

 show that all the facts can be read off in a light that harmonizes 

 with his adopted wind theory. Mr. Croll has not the literary 

 dexterity and skill which eminently characterize Dr. Carpenter's 

 pen; but he, as much as any man, knows the manifold physical 

 bearings of the vexed question ; and while on the one side the 

 exposition of an argument is adorned with literary grace, on the 

 other the real scientific value of facts and observations is more 

 promptly apprehended. 



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