But the education of a people cannot be confined within business limits. The learning of mere facts cannot advance the discipline of minds beyond a certain point. A truly intelligent people wishes to know the causes of facts, the reason of things, their relationships, their history, the logical 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 which are impressed 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 by a geologist who is commissioned to report on a large territory—to map an entire county—in one field season.
Secondly: 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 investigation is so limited, that it has become necessary to divide it up into many parts. The collections of deep sea soundings made by the British ship Challenger have been distributed 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,
