WAR GEOLOGY 175 



was well illustrated by Hindenburg's celebrated vietory in the Mazurian 

 Lake region of East Prussia, where 80,000 or 90,000 Russians are said to 

 have been captured and thousands more killed or drowned in impassable 

 swamps. An investigation and careful mapping of the Mazurian region, 

 before the war, had revealed that certain swamps possessed a firm bottom 

 and could be safely traversed by troops, while others of miry bottoms were 

 quite impassable. It was further found that differences in the aquatic 

 plants growing in the two types of swamps gave a reliable clue to the dif- 

 ference in the character of the bottoms. This knowledge permitted the 

 Germans to drive the Eussians into the impassable morasses, while their 

 own army traversed other swamps with impunity. 



This Eussian disaster also serves to illustrate the necessity for an intel- 

 ligent and alert appreciation on the part of the higher military authorities 

 of the possible uses of scientific information of all kinds concerning a field 

 of battle. The Germans themselves give the Eussian scientists credit for 

 initiating studies in agro-geology — the science of the distribution of plants 

 with reference to geological conditions — in the swamp districts of Eussia 

 adjacent to the Mazurian Lake region. 



When the complete story of the war services rendered by geology has 

 been written, there will doubtless appear many instances in which highly 

 technical knowledge has been required to solve obscure problems and where 

 comprehension of the possibilities of such assistance was a prerequisite. 

 Two such instances may be cited, both from the experience of the British 

 army. 



x\t one time it became very desirable to ascertain tne source of materials 

 used by the enemy in concrete work at a certain locality. After puzzling 

 over this problem for a while a microscopical petrographer was called into 

 consultation. His examination of thin sections permitted him to identify 

 the material in question as volcanic rock of peculiar character, known to 

 occur at an accessible locality in the enemies' territory. 



In another place the troops at the front engaged in tunneling in cer- 

 tain formations were greatly afflicted by sores of special character. Three 

 thousand to four thousand were incapacitated. The medical corps could 

 not understand the prevalence of this trouble in restricted areas. Finallv, 

 the clay material of the tunnel walls was closely examined and found to 

 act like fullers' earth in removing the natural greases from the skin, 

 which thus dried and cracked, permitting ready infection under the con- 

 ditions of trench life. 



The lack of an intelligent understanding of the importance of geolog- 

 ical conditions has certainly contributed to many military difficulties. 

 For example : Within the territory of one of the countries opposed to the 



