750 



SGIENGE. 



[N. S. Vol. V. No. 124. 



its occasion in the too insistent implication 

 of the author of the paper under review 

 that the observations whose validity he 

 questions were limited to those made chiefly 

 from a passing vessel. Of the latitude 

 covered by the observations of Chamberlin 

 and Salisbuiy about 8° 30' lay south of 

 the tract seen by Professor Tarr, and about 

 4° 30' lay to the north of it. If the total 

 distribution of observations be divided into 

 three parts, 8° 30', 5° 30' and 4° 30', in 

 order from south to north, Professor Tarr's 



prerequisite is neglected, although an ex- 

 plicit statement covering this common ter- 

 ritory had been made by Professor Salis- 

 bury {Journal of Geology, Vol. III., 1895, 

 pp. 876-877). 



What are the respective conclusions rela- 

 tive to this common tract? Professor Tarr 

 insists upon general glaciation. Salisbury 

 and Chamberlin believe in general glacia- 

 tion with the exception of some high peaks 

 and lee faces. Of the exceptions named 

 by them none was visited by Professor 



Fig. 2. Dalrymple Island — Tj'pe of ungiaciated topography, 

 also Jour. Geol., Vol. 11., 1894, p. 661.) 



(Bull. Geol. Soc. Am., Vol. VI., pp. 219; 



observations fall within the middle division 

 and cover less than one-third of the whole. 

 It appears, therefore, that the testimony 

 of 5° 30' is being urged to set right the testi- 

 mony -of 18° 30' in a matter of general con- 

 clusions. In such an attempt it would 

 seem altogether imperative that an author 

 urging conclusions from the minor fraction 

 should have ascertained, with scrupulous 

 care, whether his own observations within 

 that fraction confirmed or contradicted the 

 coincident part of those made upon the much 

 wider tract. Singularly enough, this vital 



Tarr. There is, therefore, no direct obser- 

 vational conflict. More than this, no ob- 

 servations of the one party demonstrate 

 glaciation where the other thought it ab- 

 sent. The grounds for an issue are, there- 

 fore, rather tenuous. The two sets of ob- 

 servations are in reality rather confirma- 

 tory than conflicting. The issue has arisen 

 from an attempt to adjudicate the whole 

 coast by a fraction which happens to be in- 

 termediate in type, having been neither 

 strongly subjugated by glaciation nor left 

 conspicuously intact. 



