GEOGRA PIIIC L I TEH A TUIiE 1 25 



type. The type specimen of the pie(hnont «hicier is the ^hlla.«piIm ice 

 slieet of Alaska, while the type for the vast eontiiientul n'neiers of the 

 ice age is found in Greenland. "The niatrni licence of the field for uiacial 

 study in North America has oidy heen api)reciated within recent years, 

 and is still nnrecou;ni/.ed outside of a limited circle of special students," 

 but the recognition must extend under this forcible presentation. 



A student of the European Alps and the Southern Alps of New Zealand, 

 both famed for glaciers ; the explorer of several glaciers of the higli Sierra ; 

 the discoverer of Malaspina glacier and the sole student of the ice-fielils 

 high on the slopes of Mount St Elias; an exjierienced investigator of the 

 glacial deposits and glacial history of Unite<l States from Atlantic to IV 

 cific, Professor Russell is well qualitied to prepare a reading lesson on 

 glaciers, and his experience crops out between the lines on every page. 

 Perhaps half of his admirable pictures are from photographs of his own 

 making, and although the pronoun in the tirst person seldom appears, a 

 third or a half of the descriptive paragraphs— and these make up most of 

 the book — represent personal work. Thus the chapters have an attractive 

 air of freshness and realness. This strong personal element, which gives 

 the treatise its greatest value, has apparently afTected the arrangement of 

 contents, giving the work the form of a narrative rather than the sym- 

 metry of a monograi)h. The first chapter is an introduction, in which 

 definitions and general features are set forth. After enumerating the 

 "leading characteristics of glaciers," the author proceeds thus to answer 

 the question, " What is a glacier? " "As a provisional definition, it may 

 be said that a glacier is an ice body originating from the consolidation of 

 snow in regions where secular accumulation exceeds melting and evapo- 

 ration, I. e., above the snow line, and flowing to regions where waste 

 exceeds supply, ;. e., below the snow line" (page 16). He then describes 

 glacial abrasion, smoothed and striated surfaces not produced by glaciers, 

 special features of glaciated surfaces, glacial deposits, glacial sediments, 

 and changes in topography produced by glaciers, all witii less repetition 

 in treatment than in titles. The second chai)ter relates to the general 

 distribution of the glaciers of North America, and then follow five chap- 

 ters devoted respectively to the glaciers of the Sierra Nevada, the glaciers 

 of northern California and the Cascade mountains, the glaciers of Canada, 

 the glaciers of Alaska, and the glaciers in the Greenland region, these 

 chapters containing more than half the volume and most of the value of 

 the book. There is a cliai)ter on the climatic changes imlicated by the 

 glaciers of the Ice Age and another on the movement of glaciers, while 

 the tenth and last chapter is a suggestive and attractive discussion of the 

 life history of a glacier, in which the extended ob.servations and reflec- 

 tions of the author are summarized. 



The strong points of the work are its vividness and trustworthiness ; 

 the arrangement might have been improved, a few trifling errors in the 

 orthography of names might have been corrected, and the general scien- 

 tific dis('ussion might have been strengthened, but teachers and others 

 are to be congratulated on having at last— and for the lii-st-a thoroughly 

 reliable popular account of the glaciers of North America. 



