Archaean time in geologic history answers to pre-historic time in human history; all is dark and uncertain, though we are probably safe in assuming that there was more strife and turmoil among the earth-building forces than there has ever been since. The body of unstratified rock within the limits of North America may have been much greater than is supposed, but it seems to me impossible that it could have been anything like as massive as the continent now is. If this had been the case there would have been no great interior sea, and no wide sea-margins in which the sediments of the stratified rocks could have been deposited. More than four fifths of the continent is of secondary origin and shows that vast geologic eras went to the making of it. It is equally hard to believe that the primary or igneous rocks, where they did appear, were sufficiently elevated to have furnished through erosion the all but incalculable amount of material that went to the making of our vast land areas. But the geologists give me the impression that this is what we are to believe. Chamberlin and Salisbury, in their recent college geology, teach that each new formation implies the destruction of an equivalent amount of older rock--every system being entirely built up out of the older one beneath it. Lyell and Dana teach the same thing. If this were true, could there have been any continental growth at all? Could a city grow by the process of pulling down the old buildings for material to build the new? If the geology is correct, I fail to see how there would be any more land surface to-day then there was in Archaean times. Each new formation would only have replaced the old from which it came. The Silurian would only have made good the waste of the Cambrian, and the Devonian made good the waste of the Silurian, and so on to the top of the series, and in the end we should still have been at the foot of the stairs. That vast interior sea that in Archaean times stretched from the rudimentary Appalachian Mountains to the rudimentary Rocky Mountains, and which is now the heart of the continent, would still have been a part of the primordial ocean. But instead of that, this sea is filled and piled up with sedimentary rocks thousands of feet thick, that have given birth on their surfaces to thousands of square miles of as fertile soil as the earth holds. That the original crystalline rocks played the major part in the genealogy of the subsequent stratified rocks, it would be folly to deny. But it seems to me that chemical and cosmic processes, working through the air and the water, have contributed more than they have been credited with.