156 CLASSIFICATION OF THE PUBLIC LANDS. 



which may be now or at some later time of interest and value in other 

 ways. These " by-products " of the process of land classification are 

 of many kinds. Some are of value to home seekers and the public at 

 large, others directly concern engineers and mining men, and still 

 others are of present interest chiefly to scientists. 



DATA OF DIRECT INTEREST TO THE PUBLJC AT LARGE. 



While all information obtainable concerning the public domain is 

 of ulterior interest to the people, information relating to such matters 

 as the surface features, water supply, and character of the soil of a 

 piece of land may prove to be of vital importance to the present or 

 prospective settler. It is not practicable for the Geological Survey 

 to make an exhaustive study of these features, but in the work of 

 classification a certain amount of such information is always recorded. 

 Thus, a map, supplemented by a written description, of each town- 

 ship examined for its mineral content is placed in the Survey files, 

 showing in a rough way the agricultural character of the country. 

 From these records it is possible to tell whether a section of land is 

 suitable for dry farming or is adapted only to grazing, to obtain some 

 idea of the number and size of the trees upon it, or to prepare a pre- 

 liminary report as to its irrigability. 



The field men engaged in work relating to land classification also 

 record the position and size of all springs and water holes which they 

 may find. This information is of direct value to the settler, but it 

 also has another more general use. The more valuable agricultural 

 lands of the public domain are rapidly passing into private owner- 

 ship under the various settlement laws. It is recognized that most of 

 the lands remaining are chiefly valuable for grazing or other uses not 

 dependent on tillage, although the present laws do not adequately 

 provide for their acquisition for these other uses. Congress has 

 already given consideration to this problem and will doubtless reach 

 a solution of it within the next few years. One of the most important 

 factors to be considered in arriving at that solution will be the rela- 

 tion of the watering places to the range lands, for such lands can not 

 be used without an accessible water supply. The accumulation of 

 these data, therefore, in addition to being immediately useful to 

 settlers and others, will be valuable in solving one of the public-land 

 problems now confronting our lawmakers. 



In studying and mapping a coal or phosphate bed it is necessary 

 also to observe rather closely the geologic structure or attitude of 

 the inclosing rocks. In some areas structure may have no bearing 

 on mineral-land classification and yet may be valuable in deter- 

 mining the probability of obtaining a good well or of striking 

 artesian water. The principles governing the flow of underground 



