139 



Wabash Studies. V. A Topographic Map of the 

 Terre Haute Area. 



Charles R. Dryer. 



The west sheet, c<)^■el•ing an area about five miles square, was pre- 

 sented to the Academy iu 1909 and a poor photographic copy of it was 

 published in the Proceedings for that year. The east sheet, covering an 

 area six by seven miles, is now completed. The two sheets cover a strip 

 five to six miles wide north and south and twelve miles long east and 

 west extending across the Wabash valley. The original draught and trac- 

 ing are on a scale of six inches t(j the mile and tlie contour intervals are 

 hve, ten and twenty feet, according to the relief. The datum planes used 

 for the west sheet were the levels of the "\"andalia and Big Four railroads. 

 After that was completed the United States Geological Survey establislied 

 bench marks in the area which were used for the east sheet, although 

 found to be o.ti.j feet above those of the west sheet. 



On the east sheet levels were run with a dumpy level along east-west 

 lines one mile apart and the intervening spaces were filled in with a hand 

 level used on a staff. The levels of the city engineer's office reduced to 

 U. S. G. S. (latum, were used v.iierevfr availal)le. The work was all done 

 by students of the Department of Geography and Geology of the Indiana 

 State Normal School. In all aI)out forty different persons worked upon it 

 during periods varying from six weeks to thirty-six weeks each. Of 

 these Melvin K. Davis and Garl H. Barker became the most pi'oficient, and 

 to them was assigned the plotting and final draft of the map. 



The map is not good enough for sewer, drainage or hydraulic work, 

 but would be of some value for highway and railroad location. For geo- 

 graphic and geological purposes it is far better than none. Its final dis- 

 placement by a better one will not destroy the values of the experience 

 obtained by its makers or the facility it alfords for general field work. 



