THERMAL CONDUCTIVITIES OF ROCKS 281 



puted in terms of feet per degree F. for the fields where tests have been 

 made is given. 



An explanation is also given of several figures on which are drawn 

 contours on 8o° F. isothermal surface for wells of the Garber field, contours 

 on 100° F. isothermal surface for a portion of the Cromwell field, gradient 

 depth to ioo° F. for three wells located on the Haverhill, and contours for 

 ioo° F. isothermal surface for wells in the Eldorado, Kansas, field. 



Variations in Oklahoma and Kansas fields. — Temperature observations 

 have been made in twenty-four fields in Oklahoma and Kansas. Since 

 the only wells available for testing happened to be temporarily abandoned 

 when the fields were visited, the data from most of these fields are too 

 meagre for conclusions to be drawn regarding the variation of temperature 

 with geologic structures. However, it is interesting to note that in only 

 two or perhaps three fields the data collected tended to disagree with the 

 findings of van Orstrand's previous work in Wyoming and California (' Some 

 Evidence on the Variation of Temperature with Geologic Structure in 

 Wyoming and California Fields.' Economic Geology, vol. 21, no. 2, 1926). 



Other uses for temperature data. — New and important uses for the 

 accurate temperature data that are being collected in Oklahoma are 

 mentioned. 



Conclusions. — As a whole, the results obtained in Oklahoma to date on 

 the temperature problem are neither consistent nor inconsistent enough to 

 justify any general conclusions. The results indicate, however, that the 

 problem is not simple and that it will probably be solved by the collection 

 of additional accurate data in the fields and in non-productive areas, 

 supplemented, perhaps, by some careful work on the heat-conducting 

 properties of sedimentary rocks in a well-equipped laboratory. 



Measurements of Temperature in Boreholes. 



By G. Friedel and V. Makowsky. 

 Le genie civil, vol. 45, no. 23, 1929, pp. 568-569. 



Owing to the fact that the use of medical or other types of maximum 

 thermometers at depths over 1,000 or 1,500 m. requires their inclosure 

 in strong steel boxes and that the indications of the thermometers are 

 to be corrected for high and very uncertain pressures, the use of open- 

 tube thermometers without a graduation scale is proposed. The tube of 

 such a thermometer is cut obliquely at its upper end at an angle of about 

 45 or a little more to the axis of the tube. The reservoir and the tube are 

 filled with mercury so that the latter may rise to the orifice at a temperature 

 which is certainly below that expected at the point of measurement. 



Two or three thermometers prepared in this way can be lowered, pro- 

 tected by a simple sheet-iron box filled with clear water, as the pressure 

 will not have a notable effect on the open tube. The thermometers should 

 be left in the borehole for about 24 hours. 



At a depth fixed for the measurements the mercury will rise above the 

 open end of the tube and one part of mercury will escape. After the removal 

 of the thermometers they are heated side by side with a graduated thermo- 

 meter until the mercury rises again up to the orifice ; this moment will 

 show the temperature measured in the hole at the desired depth, and its 

 amount can be read from the graduated thermometer. 



Temperature curves obtained from measurements made with this type 

 of thermometer in the potassium mines in Alsace and in the saliferous basin 



