28 C. E. VAN ORSTRAND 
Because of the difficulty experienced in obtaining wells located at 
a sufficient distance from edge water, the evidence on the variation of 
temperature over sand lenses is not very complete. However, Mc- 

—-------- Top of fort Riley limestone. 
100° F. isogeothermal surface. 
EL DORADO, KANSAS 
Fic. 9.—I.ocal variation over granite ridge, El] Dorado, Butler County, Kansas. 
Cutchin’s (29) observations in the Haverhill field, Butler County, 
Kansas (Fig. 10), located about 7 miles south of El Dorado, Kansas, 
show a well defined variation. The numbers on the right of the well 
locations (Fig. 10) represent the depths at which a temperature of 
550 
