10 



however, that the quotations are not more extensive (F) and in some cases 

 better selected — for example, the observations of Sir Wyville Thomp- 

 son in the antarctic region are ignored. It is to be regretted even 

 more deeply that the author speciously defends his own blundering 

 attempt to measure the rate of ice motion in Muir glacier instead of 

 accepting the excellent series of measurements by Professor H. F. 

 Reid. (G) In 1886 he sought to measure the movement of this magnificent 

 glacier by ' 'observations * * * with a sextant upon pinnacles of ice 

 recognizable from a base-line established upon the shore" (page 47), and 

 obtained a value of 70 feet per day. In 1890 Professor Reid measured the 

 ice flow at the same season by theodolite readings on a line of flags at 



(Note F) Mr. McGee differs from the Edinburgh Review for April, 

 1892, which, in an able article on Dr. Wright's larger work on the Ice 

 Age, says, "From practical work he was led on to the eminently useful 

 task of summarizing, for the benefit of the general reading public, the 

 mass of information accumulated by himself and his coadjutors ; and he 

 brought to its execution the valuable qualifications of wide persona} 

 experience, quiet enthusiasm for his subject and a disinterested love of 

 truth. He might, indeed, have trusted more than he has done to 

 his own literary capabilities, for in his laudable desire to let his fellow 

 laborers speak for themselves, he has unnecessarily, here and there, given 

 to his admirably illustrated volume somewhat the air of a compilation." 



(Note Gr) It is the opinion of high authorities that both measurements 

 were substantially correct. Mr. McGee is either very unfair or ignorant 

 of the literature of the subject in all of which causes of difference appear. 

 (See Man and the Glacial Period, p. 47; Am. Geologist, December, 1892, 

 page 397; Mr. Warren Upham in "Pleistocene and Present Ice Sheets" at 

 the Ottawa meeting of the Geological Society of America; Professor H. P. 

 Cushing, Am. Geologist, October, 1891, pp. 215, 216; Scientific American 

 for April 9, 1892, p. 227 ; and Professor H. F. Reid, vol. iv. Nat. Geog. 

 Mag. pp. 41, 42.) Whether ignorant or not, Mr. McGee is certainly unfair, 

 for Professor Wright on the very page referred to did accept Professor Reid's 

 measurements. He even speaks of them as "by methods promising greater 

 accuracy than could be obtained by mine." Mr. McGee calls on Professor 

 Wright to accept Professor Reid's measurements in place of his own when 

 both Reid and Cushing say (did Mr. McGee read it ?) that the ice must have 

 moved faster in Wright's time. In 1890 it had retreated 3000 feet and was less 

 than half as high. In 1886 it was apparently advancing, in 1890 retreat- 

 ing. Prof essor Reid anticipated it would continue to retreat; but Muir Gla- 

 cier is a coquette, and, in 1892, Professor Reid found it was again advancing. 



