SKETCHING. 107 



location is unnecessary. Any point on or off the road which affords an 

 outlook will serve. As a rule, frequent stations should be made, and one 

 should not attempt to sketch at great distance unless the conditions are 

 favorable, as they may be in a country of large, bold features. It may be 

 necessary to travel over all the roads which have been traversed and to 

 climb many hills in order to sketch the entire area satisfactorily. On the 

 other hand, in a different region the entire area may be sketched by a 

 limited amount of travel or from a few elevated points. In a low country 

 of small features much travel will be required, as these details must be 

 sketched from near points. In a bold country of high relief, which may 

 be sketched entirely from a few points, care must be exercised in the 

 selection of sketching stations. From a great altitude the lower details 

 will be dwarfed and will measurably disappear, while from low points the 

 relations, forms, and masses of the greater elevations cannot be properly 

 seen. In. such a country stations at different elevations must be selected in 

 order to see all parts of the country to the best advantage. The extreme 

 summits will prove of little service as sketching stations. 



Sketching is artistic work. The power of seeing topographic forms 

 in their proper shapes and proportions and of transferring these impressions 

 to paper faithfully is of all acquirements one of the most difficult to obtain. 

 The difficulty is increased by the necessity of expressing form by. means of 

 continuous contour lines at fixed intervals. This work involves a knowl- 

 edge of the elements of structural geology and good judgment in applying 



them. 



Every map, whatever its scale, is a reduction from nature and conse- 

 quently must be more or less generalized. It is therefore impossible that 

 any map can be an accurate, faithful picture of the country it represents. 

 The smaller the scale the higher must be the degree of generalization, 

 and the farther must the map necessarily depart from the original. 



Now, it is in this matter of generalization that the judgment of the 

 topographer is most severely tested. He must be able to take a broad as 

 w.U 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 features. Thus, and thus only, will he be competent to maV- just 



