Topograjphio Models. 259 



A method used by Mr. F. H. King in the preparation of his 

 large map of the United States is described by him in a letter to 

 Messrs. Harden, and published by them in the place mentioned. 

 A solid block of plaster is used, — the contoured map being trans- 

 ferred to it — and the plaster is carved down to produce a series 

 of steps like those made by building up the contours. The 

 shoulders are then carved down to produce a continuous surface. 

 This method is one of the best of those that requii-e carving 

 instead of modeling. 



Many other methods of producing relief maps might be men- 

 tioned, but, as most of them have been used only to make special 

 models, they need not be described. The method that has been 

 more used than any other still remains to be described. It is that 

 which the writer has used almost exclusively, and consists in 

 building up the model and modeling the detail, instead of carv- 

 ing it. It is a maxim of the modeler that the subject should be 

 built up as far as possible, should be produced by adding bits of 

 clay or wax, or other material, and not by carving away what is 

 already on, — by addition and not by subtraction. This may be 

 illustrated by a reference to the methods of the sculptor. The 

 bust, or figure, or whatever the subject may be, is first modeled 

 in clay or wax; from this model a plaster mould is made, and 

 from this mould a plaster cast is taken. This cast is called the 

 original, and the finished production, whether in marble, bronze, 

 or any other hard substance, is simply a copy of this original. 

 No one ever attempts to produce the finished bust or figure 

 directly from the object itself. Even where the artist has for 

 a guide a death mask, the procedure does not change. The bust 

 is first made in clay, and this clay model, as a rule, contains all 

 the detail which subsequently appears in the finished bust. I]t 

 seems strange, therefore, that the relief map maker should use a 

 method which the sculptor, with infinitely more skill and judg- 

 ment, is afraid to use; and this on subjects that do not differ as 

 much as might be imagined. 



The contour interval to be used depends on the use to which 

 the model is to be put. It is not always necessary 'to carry into 

 the model all the contour lines upon the map: I may go further 

 and say, that it is not always desirable to do so. The number to 

 be used depends to some extent on the skill of the modeler. As 

 already stated, the contours are only a means of control, and one 

 modeler requires more than another. To build into a model every 



