180 



SCIENCE. 



[N. S. Vol. I. No. 7. 



to take a broad as well as a detailed view 

 of the country; he must understand the 

 meaning of its broad features, and then 

 must be able to interpret details in the 

 light of those featiu-es. Thus, and thus 

 only, wiU he be competent to make just 

 generalizations" (p. 107). 



THE UPLIFT OF THE EXISTING APPA- 

 LACHIANS. 



The origin of topogTaphic forms has as yet 

 received so small a share of attention from 

 the greater number of field geologists and 

 geographers, and the presentation of the 

 problems involved has as yet gained so Uttle 

 attention from teachers in schools of higher 

 grade that contributions to the subject ft-om 

 a man of Mr. Gannett's experience and 

 qualifications are of great value. Yet in 

 certain parts it seems to the writer that his 

 plan of presentation is open to criticism . He 

 states first that topographic features origi- 

 nate by uplift, by deposition and by erosion. 

 Under the heading of uplift, he writes : 

 " The ridges and valleys of the Appalachian 

 region are the result of uphfts, with numer- 

 ous sharp folds and faults, which raised at 

 various angles an alternation of hard and 

 soft beds, from which erosion has since 

 carved the existing alternations of ridge 

 and valley" (p. 109). In spite of the 

 qualifications of a preceding paragraph, to 

 the effect that forms produced by uplift are 

 during and since their rise greatly carved 

 hj erosion, the reader can hardly acquire a 

 correct understanding of the facts concern- 

 ing the Appalachian ridges and valleys from 

 Gannett's statement ; nor can he easily ac- 

 quire ft'om the Appalachians an idea of the 

 nature of forms produced by uplift mth 

 folding and faulting. Such forms can be il- 

 lustrated best by the selection of young 

 topographic districts, on which erosion has 

 as yet made little advance. Our western 

 country possesses many and excellent ex- 

 amples of this class. Furthermore, it is no 



more allowable to describe the Appalachian 

 ridges and valleys as the ' result of uplifts, 

 with numerous sharp folds and fault ' than ' 

 it would be to associate the fiords of Labra- 

 dor with the ancient deformation of the old 

 rocks of that region. The ApiDalachian up- 

 lifts with folds and faults have long ago been 

 consumed ; the uplift fi-om which the ex- 

 isting ridges and valleys are carved was a 

 broad arcliing of the region, without folding 

 or faulting of perceptible measure. It is 

 true that the uxJ-arched mass possessed a 

 structure given ages before by folding and 

 faulting ; but that more disorderly kind of 

 uplift had little in common with the broad 

 and even uplift of the region by which its 

 present relief was initiated. The essaj' by 

 Hayes and Campbell, alreadj' referred to, 

 gives sufficient demonstration of this im- 

 portant conclusion. 



A FRENCH OPINION. 



The following abstract from an essaj' en- 

 titled 'L''age des formes topograpMques' by 

 A. de Lapparent, the eminent geologist 

 (Eevue des questions scientifiques, Oct., 

 1894), expresses an opinion concerning the 

 personnel of a topographic corps that is 

 somewhat surprising as coming from France, 

 where we had supposed that the propriety 

 of the military control of official geographical 

 work was unquestioned. De Lapparent 

 ■m'ites in effect : The distraction of our 

 professional geographers bj' the studj' of ar- 

 bitrary political boundaries in the early part 

 of this centurj^ would have been lessened if 

 the work of detailed mapping had been left) 

 to men readj- to interest themselves in the 

 many questions provoked by the manifold 

 forms of land relief. Unfortunatelj^ the re- 

 verse was done in decreeing that cai-to- 

 graphy should be exclusivelj^ a ftinction of 

 the department of war. Up to 1830 there 

 was in France an excellent institution, that 

 of the geographical engineers. Well pre- 

 pared in the Ecole polj'technique, the 



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