82 Notice of a Geological Model. 
be the hand and the eye of the artist. The interesting and ac- 
curate effect incidental to a picture, thus formed in relief, is appa- 
rent enough when the observer brings his eye to the level of any 
‘point whatever on the model ;—the summit of a mountain, the 
point of a bluff, or the curve of a river, for instance,—from 
whence all that he needs in obtaining at ease and convenience a 
view of the surrounding scenery, is accomplished. 
For topographical observations, for rapid reconnoissances, for 
tracing routes for railroads, for canals, or for ordinary roads and 
communications, the model system presents facilities for number- 
less practical purposes, and may be the means of saving a great 
of preliminary labor and expense, on such occasions, in a 
mountainous or forest district. 
In all such regions, it is common to adopt as the best, because 
they are the most natural and the most permanent, lines of de- 
marcation, the elevated chains, the elongated ridges, the ranges 
of highlands or platforms which divide the sources of rivers and 
influence the descent of drai or to constitute the rivers 
themselves, as they flow betwe ithesi ges, the boundaries. 
of local and territorial jurisdictions. All of these are particularly 
and necessarily prominent features in a model; and these, the 
most sublime and most imperishable eioensgsibii in all countries, 
have with propriety been selected as the most fitting for such 
conventional purposes. Had a model, however roughly con- 
structed, been in existence to illustrate the physical geography of 
what is termed “the disputed territory” in the northeast, half a 
century of embarrassment and conflicting opinions, and local dif 
ficulties, might have been saved to the interested parties. It is 
ni late, even at this hour, to exhibit in this way, all the 
topegrebaicn! characters of that region; to represent those great 
natural features, suggested for lines of international boundary. 
All details applicable for this purpose are but now in progress 
of collection. From their arrangement we may expect to result 
the clearing up of existing obscurities ; a more accurate construc- 
tion of terms, and the adjustment of important points, now at 
issue. 
Models are peculiarly adapted to the exhibition of geological 
phenomena. For ordinary convenience of transportation and — 
portability, no doubt maps are best adapted, for the library, or for 
the use of the traveller. But for public and more enlarged ob- 
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