Page:Popular Science Monthly Volume 36.djvu/237

Rh rising and sinking of continents, and this solution of the problem has not been contradicted till very recently. There is a kind of suggestion with which great men, to whose minds the world pays deference, inspire their contemporaries when they give any view the weight of their approval, which is at the same time detrimental to progress in science. In this way many an error has been generally accepted without further proof.

Suess does not ask for an unjudicial acceptance of his theory, but has published the whole course of his investigations, with his proofs, in a great work, the "Antlitz der Erde" ("The Face of the Earth"), in which he has examined the signs of changes in the level of the ocean, so far as they have been observed in all known parts of the earth and through all the geological periods. His exposition points to a synchronism of overflows and uncoverings of the land over extensive regions. This result has impelled him to oppose the prevailing doctrine of upheavals and depressions of the land. Aside from the fact that the supposed elevation of the continents is problematical in itself, such movements could not go on over the whole earth at the same time and in the same direction. Changes in the level of the waters, on the other hand, would be of the general character which the survey of the phenomena indicates, for a free rising of the water, even under local influences, would at once make itself felt over the whole surface of the earth.

Suess's studies of the causes of the rising and falling of the waters brought him to the following conclusions: The ocean beds were produced by the sinking of those parts of the earth's surface that correspond with them. The uneven shrinking of the globe is a consequence of its continuous cooling. Every new subsidence of the sea-bottom causes a falling of the water. Elevations of the ground take place too. The bottom of the ocean is incessantly receiving detritus from the overflowed land, of which the water brings down as much as it can hold; this tends to raise the level of the ocean. Yet Suess concludes that these processes are not adequate to explain the full measure of the primitive movements, and reserves judgment on that point.

The present author has gone further into this subject, in an article in the "Zeitschrift für wissenschaftliche Geographie," although he has not concealed the existing difficulty. Unfortunately, Suess's deductions were not before him when he prepared his paper. That essay, building in part on similar researches, accepts contraction as the sufficient cause for the fluctuations of the sea. According to the now prevailing views, which have, however, been very recently contradicted by investigators of repute, the constant loss of heat from the interior of the earth produces a steady shrinkage of the globe. From time to time the tensions in