14 New voRic state museum 



afford a general outline of the information collected and its bearing 

 upon the work, the following paragraphs are quoted from that 

 volume : 



The benefits of the studies have been twofold and reciprocal. On 

 the one side the ]jractical planning of the enterprise has constantly 

 required an interpretation of geologic conditions as a guide to loca- 

 tions and methods and on the other the extensive investigations 

 carried on have given an opportunity for practical application of 

 geologic principles under conditions seldom offered and the data 

 secured in additional explorations serve to make the detail of some 

 of these complex features now among the most fully known of their 

 kind. Examples of such cases are (a) the series of buried pre- 

 glacial g"orges (as in the Esopus, and Rondout and Wallkill and 

 Moodna valleys) and (b) the completed geologic cross sections 

 (such as the Rondout valley, the Peekskill valley, Bryn Mawr, etc.) 

 and (c) the numerous additions to the knowledge of local rock con- 

 ditions (such as that at Foundry brook, Rondout creek. Coxing kill, 

 Pagenstechers gorge, Sprout brook, and others). 



Almost every locality has its own specific problem and its own 

 peculiar differences of treatment and interpretation of features. 

 Nearly all of the studies here presented came to the attention of the 

 writer and others in the form of definite problems or questions 

 involving an interpretation of geologic factors and an application to 

 some engineering requirement. Some of these questions 

 are the location of buried channels beneath the drift, the character 

 and depth of the drift, the kind of bedrock, the condition of bedrock 

 for construction and permanence of tunnel, the underground water 

 circulation, the occurrence of folds and faults, the position of weak 

 zones, the depth required for substantial conditions, and many other 

 similar problems. 



The cooperation of the geologist has likewise been sought in 

 solving the difficulties at Panama, though unfortunately it appears 

 this was not secured until the plans were formulated and the w^ork 

 of construction well under way. Many problems encountered in the 

 work were of the kind that required the experience and information 

 of the trained specialist. Some of the more important ones were 

 related to the locations for the locks and dams, for which the element 

 of security was critical, and to the availability of the local resources 

 in building materials. It seems probable that if the results of the 

 survey had been available at the start they would have had even 

 greater value in guiding the course of operations. 



In combining the work of the geologist and engineer, Germany 

 seems to be in advance of other countries. Public improvements 

 like canals, railroads, and the regulation of streams are undertaken 

 only after investigations of the geological factors that infiuence the 



