708 



SGIENGE. 



[N. S. Vol. IV. No. 98. 



lation of detailed information than fell to 

 the fortune of his colleagues further east 

 who had some difficult knots to untangle. 



I have read the report on the Fourth 

 Geological District of New York more 

 often, with more assiduity and precision 

 than I have read any other geological book. 

 I have studied it for information, for guid- 

 ance in the field during nearly twenty 

 years. I have perused it critically, pur- 

 posely blind to its merits and alive to any 

 discrepancies, shortcomings or errors ; and 

 I have, too, endeavored to read it in the 

 spirit which dictated it. To-day I do not 

 hesitate to say that I know no other work 

 of this character so distinguished for its 

 fidelity to the facts, so strongly stamped 

 with accuracy of observation. The work 

 begun by Prof. Hall in this region fifty-nine 

 years ago stands to-day squared with the 

 truth as it stood fifty- three years ago, when 

 his final report was rendered. 



In 1837 western Kew York was only a 

 sparsely settled country. It had already, in- 

 deed, centers of civilization. Buffalo was its 

 most populous point ; Eochester was a rap- 

 idly growing town, and there were various 

 thrifty villages dotting the valley lands. 

 Their population had been drawn very 

 largely from the New England towns ; the 

 Phelps and Gorham Company, and the Hol- 

 land Company, whose lands included nearly 

 the whole of the region, had attracted pur- 

 chasers of a superior class ; the country 

 north of the Helderberg escarpment, in the 

 lake region, and in the fertile valleys, had 

 become stippled with enterprising settle- 

 ments, which were increasing in size and 

 number under the influence of the chief 

 highway, the Erie Canal. But away from 

 the lowlands, over the high intervales of 

 the central area and the broad plateau cov- 

 ering the southern half of the district, the 

 region was largely a virgin wilderness. 

 These circumstances were, no doubt, con- 

 tributory to the simplicity of the geological 



problem, for it was in the low lands, those 

 which civilization had taken possession of 

 and rendered comfortably accessible, that 

 the greatest number of distinct geological 

 formations were present ; the Medina, Clin- 

 ton, Niagara, Salina, Corniferous, Water- 

 lime, Marcellus and Hamilton ; while the 

 highlands, the wilderness covering more 

 than one-half the area of the district, 

 proved to belong almost wholly to the two 

 divisions. Portage and Chemung. 



It is not my intention to pass in review 

 the geological determinations of Prof. Hall 

 in this district ; they are too well known. 

 The great value of the results attained 

 lies, as I apprehend it, in the stable, inde- 

 structible foundation upon which they 

 placed a large portion of the paleozoic suc- 

 cession. Let the geologist now approach it 

 from any quarter, whatever the position, 

 whatever the lever, he will labor in vain to 

 overthrow or disturb these foundations of 

 the geological edifice in New York. The 

 work was not done for a day, but for all 

 time. Upon this foundation workers of 

 to-day must build. Other foundation can 

 no man lay. 



No one has contributed so much to the 

 superstructure as has Prof Hall himself. 

 The study of this great series of fossil- 

 bearing rocks during his six seasons in the 

 field aroused in him a conviction of the 

 preeminent importance of a knowledge of 

 extinct organisms as a means of substani- 

 ating strictly geological evidence. " The 

 New York geologists have made out a clas- 

 sification of their older rocks," said Sir 

 Charles Lyell; '' let them now prove the 

 truth of it by means of their fossils." It 

 was for this very end, to prove the validity 

 of the New York Series that Prof. Hall, 

 upon the close of the Fourth District sur- 

 vey, sought and obtained encouragement to 

 carry forward purely paleontological stud- 

 ies, with results of surpassing value. To 

 the survey of the Fourth District we must 



