vi V\T. i:ki»(>im' of imjookkssj. c k. bkeciiku. 



Hui tht^ education of a people cannot be confined within 

 business limits. The learning of mere facts cannot advance 

 the discii)line of minds beyond a certain i)oint. A truly 

 intelligent people wishes to know the causes of facts, the 

 reason of things, their relationships, tlieir history, the log- 

 ical conclusions of every kind which can be drawn from 

 them by investigation. What is called modern science is 

 the endeavor to satisfy this craving of human intelligence 

 for something more and something nobler than mere facts, — 

 the instinctive conviction of our age that education must 

 be not merely accurate but also wide ; that it is shameful 

 to be satisfied with mere details; that apparently useless 

 truth is in its very nature delightful and elevating, and is 

 sure to become, sooner or later, in these hands or in those, 

 in one direction or another, and always unexpectedly, 

 useful. 



Therefore, while the plan of the Survey was practical, its 

 geologists have always kept in view whatever could help to 

 effect a thorough knowledge of the geology of the State ; 

 especially those vegetable and animal forms Avhich are im- 

 pressed upon or imbedded within the rock formations 

 which underlie the soil. 



But the publication of this branch of the geology of 

 Pennsylvania has been delayed for various reasons — chiefly 

 because the study and delineation of fossils demand the 

 entire time and exclusive devotion of those who undertake 

 it, and cannot be successfully carried on bv a geologist who 

 is commissioned to report on a large territory — to map an 

 entire county — in one held season. 



SecondU' : The collection of fossils must go first, — their 

 study and delineation is a tedious subsequent performance. 



Thirdly : The world of fossils has become so vast and the 

 number of geologists who devote themselves to its investi- 

 gation is so limited, that it has become necessary to divide 

 it up into many parts. The collections of deep sea sound- 

 ings made by the British ship Challenger have been dis- 

 tributed for study to botanists and zoologists in every 

 country in Europe, and even in America. So, in the study 

 of fossil forms, Carboniferous plants are sent to one expert, 



