36 UNIVERSITY OF COLORADO STUDIES 



touches the canyon walls or valley walls at all points be considered 

 a glacier, and a similar body of ice having all the same characters 

 except that it has been melted along the sides so that a space of one, 

 ten or a thousand feet intervenes between the ice and the wall be 

 deemed neve ? Who is to decide whether the slope of the valley sides 

 must be ten degrees, one degree or a fraction of a degree to constitute 

 a wall ? 



Other writers have set forth the general characters of a glacier, 

 rather than attempting brief definition, but even that does not enable 

 one to determine with certainty in every case whether a given ice- 

 field should be called a glacier. 



Unfortunately the word glacier is, in some portions of the Southern 

 Rockies and Sierras, coming to mean nothing more than a perennial 

 bank of ice or snow, and the writer has heard it applied to very small 

 snow-banks, indeed. This is due partly to local pride — the determina- 

 tion of every community that it shall not be outdone by rival com- 

 munities — and partly to a desire on the part of tourists and explorers 

 who get into out-of-the-way places to believe that they are making 

 discoveries of value. But neither local zeal nor explorer's enthusiasm 

 should lead to designating natural objects by names which are inappli- 

 cable. It is scientifically just as important to discover that things 

 do not exist as to discover that they do. The traveler who, by thor- 

 ough exploration of a region hitherto unknown, ascertains definitely 

 that it contains no glaciers, has rendered just as much service to 

 geographical and geological science and contributed as definitely to 

 the sum of human knowledge, as if he should discover a thousand 

 glaciers. 



A glacier is a body of ice originating in an area where the annual 

 accumulation of snow exceeds the dissipation, and moving outward 

 or downward to an area where dissipation exceeds accumulation. 

 Snow which has stood for some time becomes granular and changes 

 to ice which is granular, though that condition is difficult to recognize 

 except when the ice is considerably "weathered." The granular 

 snow is called neve or firn. Its transition into glacier-ice is gradual, 

 so that there is no sharp line of demarkation. 



