ECONOMIC RESULTS OF GEOLOGIC INVESTIGATION 95 



ical line defined accurately the vertical limits of fossils and provided 

 means for removal of difficulties where the succession is incomplete, and 

 for tentative correlation in widely separated localities, an apparatus 

 whose usefulness cannot be overestimated from an economic standpoint. 



If the man who makes two blades of grass grow where only one grew 

 before be a public benefactor, what shall be said of the geologist who 

 turns a desert into a garden? This was done by the first survey of New 

 Jersey, which differentiated and mapped the marls of that state, giving 

 a complete discussion of their nature and value. Great areas of the 

 " white sand barrens " have been converted, not into mere farm lands, 

 but into richly productive garden spots. In later years the second sur- 

 vey, now almost forty years old, did, as it is still doing, admirable work 

 along the same lines. The study of the structural geology gave a clue 

 to the causes of restrained drainage, and in not a few instances showed 

 that relief from malaria could be obtained with unsuspected ease, and 

 that many miles of noxious swamps could be converted into lands well 

 fitted for residence. 



The first survey of Pennsylvania was })urely scientific in inception 

 and execution ; economic questions had little of interest for its head, 

 and in the work their place was very subordinate to those in pure science ; 

 yet the outcome was inevitable. The study of the Appalachian folds and 

 the discover}^ of the steeper northwester]}' dip revealed the structure of 

 the anthracite region and made it possible to determine the relations of 

 the anthracite beds ; the vast extent of the bituminous area and the im- 

 portance of the Pittsburg coal-bed were ascertained during the search for 

 facts to explain the origin of the Coal Measures; the ores of the central 

 part of the state were studied with rigorous attention to detail, that the 

 problem of their origin might be solved ; but these and other scientific 

 studies brought out a mass of facts which were seen at once to possess 

 immense importance, and the reports were published broadcast. New 

 industries were established ; old ones previously uncertain became cer- 

 tain and developed prodigiously; the coal and iron interests moved at 

 once to the front, so that within two or three years after the survey ended 

 "tariff" became the burning political question throughout the state. 

 The results of the second survey were even more remarkable in their 

 influence upon the development of the commonwealth and the increased 

 comfort of the population. 



Among the earliest results of the first survey of Michigan was the de- 

 termination of the value of the salt lands and the announcement of iron 

 ore in the upper peninsula. The successors to this survey, under the 

 United States supervision, made studies of numerous localities and de- 

 termined the excellence of the ores. Unquestionably the importance of 



