TRAVERSES 



colleagues finds it possible to complete in a year. Such 

 rapid surveying could of course be regarded as furnishing 

 merely a kind of rough preliminary sketch of the geology 

 of th cs, to serve as the basis for subsequent 



detailed surveys. It may be taken as an example of 

 broad generalised field-work on the one hand, while the 

 Geological Survey of Britain stands at the opposite 

 ic, as a model of patient and elaborate detail. 



student may usefully refer to other examples 

 of such pioneering geological exploration in Western 

 America. Of these, the / >n of thi Fortitth 



/fer//r/, under Mr. Clarcn< and the Geological 



and Geographical Surrey of the Rocky Mountain Region^ 

 : Major Powell, well deserve perusal. The more 

 recent memoirs, reports, and monographs of the United 

 States Geological Survey and those of the Geological 

 Survey of Canada may also be profitably studied. The 

 "folios" of the United States Survey are particularly 

 deserving of attention. Each of them contains a series 

 nting the topography, geology, or other 

 features of a particular region, together with geological 

 sections and some pages of descriptive letterpress. 



Intermediate between the minutely detailed work of 

 rvey and the broad outlines of the early 

 American explorers come the geological maps pub- 

 lished by different governm< i urope. The Carte 

 GMogtqxe detail </< la Fmnce is a good example which, 

 with its explanatory Bulletin^ may be advantageously 

 consulted. Some of the most striking maps and sections 

 of the Kuropean continent are those prepared by the 

 Geological Commission in Switzerland. Nothing more 



