262 National Geogi^ajphic Magazine. 



as his idea of it would be if he were on the real ground itself. 

 Care should be taken, however, not to make the scales so dispro- 

 portionate as to do violence to mental impressions. Often, in- 

 deed, prominent or important features, when they will bear it, 

 may be still more effectively shown by additional exaggeration 

 in the vertical scale." The fallacy of this argument is obvious. 

 It assumes that the object of a model is to show the country as 

 it appears to one passing through it, and not as it really is — and 

 there is often a very wide difference between the two. The im- 

 pression derived from passing through a country is, if I may use 

 the term, a very large-scale impression, as any one who has tried 

 it can certify ; it is certainly a mistake to attempt to reproduce 

 this impression in a small-scale model, with the help of vertical 

 exaggeration. Even if the principle were a good one, its applica- 

 tion would be very limited. It could only be used in large-scale 

 models ; to apply it to a model of a large area — the United 

 States, for example — is obviously absurd. 



The method referred to as being now generally in use may be 

 briefly described as follows : requisites, a good contoured map ; 

 a hachured map in addition, if possible ; a clear conception on 

 the part of the modeler of the country to be represented ; and a 

 fair amount of skill. Materials : a base-board of wood or other 

 suitable material ; card-board or wood of the thickness required 

 by the contour interval and the scale ; and modeling wax or clay. 

 Procedure : reproduce the contours in the wood or other mate- 

 rial ; mount these upon the base-board in their proper relation- 

 ship ; then fill in the intervening spaces, and the space above the 

 topmost contour, with the modeling material. 



In a series of models of the Grand Divisions of the earth, made 

 about a year and a half ago, the contours of card-board were 

 made as follows : the map was photographed up to the required 

 scale, and as many prints were made as there were contour inter- 

 vals to be represented — in a model of the United States of 1,000 

 feet contour interval there were fourteen prints. Thirteen of 

 these were mounted upon card-board of the exact thickness re- 

 quired by the vertical scale, and one upon the base-board. All 

 large paper companies use a micrometer gauge, and card-board 

 can easily be obtained of the exact thickness required — even to 

 less than the thousandth part of an inch. The lowest contour 

 was then sawed out upon a scroll saw, and placed upon the cor- 

 responding line of the map mounted upon the base-board. This 



