always perfect. Some point is perhaps taken for granted, some peculiar circumstance is overlooked. Or else our explanation agrees with the facts not perfectly, but merely in an approximate manner, leaving a something still to be accounted for. Now, these residual phenomena, these very anomalies, may become the guides to new and important revelations.
In the course of my research anomalies have sprung up in every direction. I have felt like a traveler, navigating some mighty river in an unexplored continent. I have seen to the right and the left other channels opening out, all claiming investigation, and promising rich rewards of discovery for the explorer who shall trace them to their source. Time has not allowed me to undertake the whole of a task so vast and so manifold. I have felt compelled to follow out, as far as lay in my power, my original idea, passing over reluctantly the collateral questions springing up on either hand. To these I must now invite the attention of my fellow-workers in science. There is ample room for many inquirers.
Nor must we forget that the more rigidly we scrutinize our received theories, our routine explanations and interpretations of Nature, and the more frankly we admit their shortcomings, the greater will be our ultimate reward. In the practical world fortunes have been realized from the careful examination of what has been ignorantly thrown aside as refuse; no less, in the sphere of science, are reputations to be made by the patient investigation of anomalies.—Advance Sheets of Quarterly Journal of Science.
| THE CAUSES OF THE COLD OF THE ICE PERIOD. |
By Prof. J. S. NEWBERRY,
OF COLUMBIA COLLEGE.
A FEW years ago the scientific world was startled by the assertion—made by Charpentier and Agassiz, who had been studying the glacial phenomena of Switzerland—that at no very remote period, geologically speaking, the climate of the northern hemisphere had been very much colder than at present; and that the arctic conditions which now prevail in Greenland—with perpetual snow-sheets, and glaciers reaching the sea—extended as far south as the middle of the present temperate zone.
At first, seriously questioned by most, strenuously denied by some, this theory was found to be sustained by such abundant and indisputable evidence—the inscriptions left by the glaciers themselves—that it was not long before it had secured a general acceptance from geologists. Since then there has been a vast amount of. theorizing
