XV111 REPORT OF THE STATE GEOLOGIST. 



ground. Even the railroads do not appear in some of them. There- 

 fore in endeavoring to carry on this detailed work we are met on every 

 side by this great want, and much of the time that should be spent in 

 the study of the geology must be given to correcting inaccuracies of 

 the maps. 



I have made an earnest effort to remedy this deficiency as far as pos- 

 sible. With this in view I went to Washington and had a conference 

 with Major Powell, Director of the United States Geological Survey. 

 As was stated in the First Annual Eeport, the topographic work car- 

 ried on under the direction of the United States Geological Survey had 

 been completed over some twenty-four thousand square miles in the 

 center of the State. More exactly, the area covered by this work to 

 June 1, 1890, was bounded by parallels 30° and 33°, and meridians 

 97° and 99° 30'. 



These maps are engraved in sheets on the scale of two miles to the 

 inch. On this scale each square degree forms four sheets. The prin- 

 cipal points are located by triangulation, and the relative heights and 

 differences of elevation are based upon the railroad levels of the coun- 

 try. Where there is a system of railroad lines which cross one another 

 at various points a series of checks is afforded, and the degree of accu- 

 racy with which these levels are run is sufficient for the best of these 

 maps. With these levels for a basis the reliefs of the whole country 

 are determined by running lines of levels, plane table work, and baro- 

 metric observation. 



The maps are printed in three colors ; the water-courses, lakes, etc., 

 being in blue ; the contour lines, by which each difference of elevation 

 of fifty feet is shown, in brown ; and the roads, railways, and other cul- 

 tural features and lettering in black. They are by far the most accu- 

 rate maps in existence of the region which they cover, and have been 

 of great service, since they are fully sufficient for any but the most 

 detailed work or that requiring a larger scale and greatest accuracy in 

 detail. The intention was to extend eastward by this season's field 

 work. I therefore requested of Maj. Powell that the field work of the 

 present year be planned to meet our requirements more nearly, and in^ 

 stead of working to the east of the area given above that they take up 

 that area lying between meridians 99° 30' and 100°. The completion of 

 this tier of sheets would give us the topography of all the Central 

 Mineral Kegion, part of the Abilene- Wichita country, a large portion 

 of the Cretaceous area, and all of the Central Coal Field except that 



