2QO REPORTS ON THE STATE OF SCIENCE, ETC. 



about 204 m., but none of the wells situated in the region to the north-west 

 of Pressagny was so deep as that. 



Whether this anomaly can be explained by the quick rising of deep waters 

 flowing from the region of Paris to Pressagny remains unsolved, and the 

 conclusion of the authors that the waters in Pressagny are supplied from 

 south and east seems to be the most probable one. 



Anomalies observed in several other wells were less important. 



In several places waters of a temperature lower than the normal one have 

 been observed. The authors, who called these waters ' hypothermal ' 

 waters, could not find any explanation for this hypothermality. 



A long list of authors giving data for the temperature at different places 

 is added to the article. 



Internal Heat of Earth is Studied to ascertain Facts on which to 

 base Geological Principles. 



By C. E. van Orstrand, Geophysicist, Geological Survey. 

 The United States Daily, Washington, D.C., February 15, 1929. 



The question of the internal heat of the earth has been studied almost 

 from the time of the establishment of the U.S. Geological Survey in 1879. 

 In 1920 a report on geothermal data, based generally on the observations 

 made by placing a thermometer in the water flowing from the mouth of a 

 well, was published by N. H. Darton. In this report it was noted that in 

 certain areas in eastern South Dakota the rates at which the temperatures 

 increase from the surface downward vary somewhat uniformly from about 

 i° F. in 20 ft. to approximately i° F. in 45 ft. But this method of making 

 temperature tests has proved to be unsatisfactory ; therefore the author of this 

 article undertook the task of designing and constructing the apparatus 

 necessary for more accurate measurements. Two different types were 

 developed, one of which was based on the electric resistance thermometer, 

 and the other on the mercury thermometer of the maximum type. It has 

 been necessary to abandon the electric method for the present, owing to the 

 fact that the cable that will meet the requirement of withstanding the 

 dissolving action of oil and salt water must be of relatively large diameter, 

 possibly one-half or three-fourths of an inch ; it becomes of such weight 

 and proportions that it cannot be manipulated in a deep well without the 

 aid of powerful machinery. 



The machine which is being used to-day for lowering mercury thermo- 

 meters into a well by means of a piano wire consists of a steel frame and 

 reel, a standardised wheel for accurately measuring depths, and a cylindrical 

 cam which distributes the wire on the reel and thus prevents the trans- 

 mission of impacts to the thermometers as a result of the slipping of the 

 coils of wire on the reel. No power, other than hand-power, is needed. 

 It is a remarkable fact that a machine weighing 58 pounds, exclusive of the 

 piano wire, which weighs 2-7 pounds per 1,000 ft., can be used to sound 

 wells to depths of more than 4,500 ft. 



Concerning the question of the value of temperature tests scientists are 

 not yet able to give a definite answer. 



It has been assumed ordinarily that during the millions of years of the 

 earth's existence its outer layers have gradually cooled to depths of about 

 200 miles. In contrast to this hypothesis is the comparatively recent 

 supposition that practically all of the heat of the earth is due to the dis- 

 integration of radium. There are at present wide differences of opinion 



