SNOW-SLIDES AND AVALANCHES- THEIR FORMA- 

 TION AND PREVENTION. 



By B. E. Fernow. 



The question of protection against the clisastrons effects of snow- 

 slides and avalanches has been an important one for centuries in Switz- 

 erland, where it seems that not only special conditions favorable to 

 their formation exist, but where, on account of the dense settlement of 

 the mountaiDOus region exposed to their course, their destructive effects 

 are more intensely felt. So regularly, from period to period or year to 

 year, do these avalanches occur in given localities, pursuiug the same 

 track down the mountain sides, that they have their names like the 

 mounta^ius themselves, or like the geysers, which may go off at any 

 time, pouring forth their waters at irregular periods. 



Note. — The dictionaries and encyclopedias do not seem to know the word snow- 

 slide," which is the term used in the Eocky Mountain region. The word '^snow- 

 slip" is used to denote "a large mass of snow, which slips down the side of a 

 mountain and sometimes buries houses" {JVehster), while " avalanche" is defined as 

 a " large mass of snow, earth, and ice sliding or rolling down a mountain " ( JVehster), 

 " or falling down a precipice " {Ogih'ie). (To avale — to fall, descend, he lowered, old 

 French aval — towards the valley.) There exists, therefore, no definite distinct idea 

 that might belong to the one word or the other exclusively, and the words, have there- 

 fore been used as synonyms. 



The question of the formation, dangers, and preventives of ava- 

 lanches forms the subject-matter of a very interesting volume published 

 at the instance of the Swiss agricultural department, in 1881, by I. 

 Coaz, the general forest inspector of the Republic, whose personal 

 observations and experiences for many years in the work of abating 

 these dangers deserve special attention. While the conditions, atmos- 

 pheric and geologic, of our Eocky Mountain region may not coincide 

 or compare exactly with those prevailing in the Alps, yet a study of 

 the causes and effects there observed through a long series of years 

 and of the methods there employed to remove the causes and alleviate 

 the effects of these dangers of mountain life may suggest a closer ob- 

 servation of our own conditions and the invention of expedients of 

 protection better suited to our own needs. The accounts given on 

 another page of this bulletin show that the phenomenon of avalanches 



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