GEOLOGICAL METHODS IN EARLIER DAYS 29 



Did we make blunders? We simply reveled in ignorance; we 

 learned by making mistakes and by occasionally discovering some of 

 tliem. We did not know for what to look, but we looked at everything, 

 for everything was a revelation. Some of the worst errors in corre- 

 lation were due to this. Oji my third day, while day-dreaming over 

 what seemed to be a remarkable phenomenon, I lost hold of the section, 

 and in crossing the divide committed an error which affected my work 

 throughout that summer and the next. There was no opportunity for 

 revision; the western method of reconnaissance prevailed and a line 

 once covered was completed. The young men, who did the work for 

 their expenses, gained a vast amount of knowledge but not much 

 modesty; they had been found capable of doing a new type of work 

 without assistance. The rod of correction was applied somewhat more 

 than ten years later by Professor Edward Orton, Sr., but the applica- 

 tion was made so gently, so courteously, that all of us were united in 

 gratitude to the keen man who had harmonized conflicting observations 

 and had corrected errors, but had administered no rebuke to the incom- 

 petent youths who had made them. Economically, the errors were un- 

 important as they were chiefly in correlation ; the resources of state were 

 described well and the observations were recorded honestly. A group 

 of geologists were trained, who, under Orton during the third survey, 

 knew for what to look, how to look for it and, better still, how to 

 present their results. 



The second survey of Pennsylvania was ordered by the Legislature 

 of that state in 1874, forty years ago, and J. P. Lesley was appointed 

 as director. Though a survivor of the first survey, discontinued more 

 than 30 years before, he was still in the prime of his powers and, along 

 certain lines, he was perhaps the ablest geologist in the country. But 

 he had entered from the topographical side and all his work had been 

 concerned with economic applications of geology. The survey had been 

 ordered on an extensive scale that the mineral resources of the state 

 might be determined in practical detail, so that it was necessary to pub- 

 lish prompt and somewhat voluminous reports in order to suppress 

 recalcitrant legislators. In 1875 I was appointed geologist in charge 

 of the southwestern district and entered upon the work with I. C. White 

 as aid. It may be remarked in passing that, in state work, the geol- 

 ogist must contend with one serious cause of error which is unlaiown 

 to the western explorer. Sleepless nights were rare during the western 

 work, but in the civilized region, where one must live off the country, 

 there is often the terror that walketh in darkness, which benumbs the 

 geologist's intellect and blinds his eyes during the day. 



Thirty-five years prior to our advent, Henderson had completed his 

 work for the first survey and had reached the conclusion that, owing to 

 lack of exposure, the upper part of the section would never be worked 



