198 THE NEW WORLD OF SCIENCE 



whether the Government's official geologists had been called 

 upon to contribute their special knowledge to the solution of 

 military problems. Inquiry developed the fact that a great 

 range of geological questions had been submitted by the mili- 

 tary authorities, and that the members of the Survey, both in 

 the office and at the front, were busy finding the necessary 

 answers. When German " pill-boxes " were captured, the 

 Survey was asked to determine the source of the gravel used 

 in the concrete with which they were constructed, for thereon 

 hung an important question as to how effectively a certain 

 country was preserving its neutrality. The geologist was able 

 to identify, in the concrete, material which could have come 

 only from the Rhine Valley by canals across neutral territory, 

 and thus to refute the contention that the gravel was of Belgium 

 origin. In the same way the geologist was asked to discover 

 the origin of certain cements used by the Germans. When 

 between 3000 and 4000 soldiers had been rendered unfit for 

 service by septic sores which developed on the arms of men 

 tunneling through a particular geological formation, the Survey 

 geologists were called upon to ascertain the cause; and they 

 found that clay in the formation acted like Fuller's earth in 

 removing the natural oils from the skin, with the result that 

 the skin dried and cracked abnormally, rendering infection 

 easy in the unclean life of the trenches. The low plain of 

 Flanders is lacking in material suitable for road-making, so 

 the military authorities turned to the Survey for information 

 as to the nearest supplies of stone which, when crushed, would 

 make good road metal. To detect and forestall German tun- 

 neling operations, some one conceived the idea of using seis- 

 mographs to locate the origin of distant underground blast- 

 ing, and the testing of this idea was turned over to the Survey 

 authorities as the ones most familiar with the use of earth- 

 quake recording instruments. 



The medical deportment of the army required information 

 as to the geological formations likely to yield good water sup- 

 ply in large quantities, not only in France and Belgium, but 



