Africa, the Armorican, Caledonian and Algonkian systems of folding, and the Pleistocene terminal moraines, in their sum-total, even if the conclusions may be still uncertain in particular questions, yield a proof, which is difficult to shake, of the validity of our supposition that the Atlantic must be considered as an expanded rift. We have also the circumstance of decisive importance that although the adjustment of the blocks must be made on the grounds of other phenomena, especially their outlines; yet by this adjustment the continuation of each structure on one side is brought into exact contact with the corresponding end on the other. It is just as if we put together the pieces of a torn newspaper by their ragged edges, and then ascertained if the lines of print ran evenly across. If they do, obviously there is no course but to conclude that the pieces were once actually attached in this way. If but a single line rendered a control possible, we should have already shown the great possibility of the correctness of our combination. But if we have n rows, then this probability is raised to the nth power. It is not a waste of time to make clear what this implies. We can assume, merely on the basis of our first “line,” the folding of the Cape Mountains and the Sierras of Buenos Aires, that the chances are ten to one that the displacement theory is correct. Since there are at least six such independent controls, 106 or a million to one could be laid that our assumptions are correct. These figures may be exaggerated. But one must bear in mind, when passing judgment, what the increase in the number of independent controls really means.
North of the region hitherto considered, the Atlantic split bifurcates to both sides of Greenland and becomes narrower. The correspondences between the two sides of the Atlantic lose their value as proof, because their origin can be more and more readily
