Within the last few months a good deal has been written upon the question of upheavals and depressions in the crust of the earth both in the Geological Magazine and in “Nature.” By far the majority of these writers have maintained with some show of reason that depressions are the result of the deposition of material of some sort on a part of the earth where it was not previously, in consequence of which the newly loaded part sinks down, just as a weight placed upon an air cushion causes the part on which the weight rests to be depressed. This novel view has been supported by pointing to the fact that numerous instances are met with in which vast thicknesses of rocks have been superimposed one upon another, while throughout their whole depth traces of shallow or comparatively shallow water are found, it being inferred that the sedimentary deposit being the cause of the depression, the bottom sinks exactly in proportion to the amount of the deposit. The Carboniferous system has been advanced as a conspicuous instance of this state of matters; the same holds true of the lower Old Red Sandstone, which appears to have been deposited in lakes.