Let us suppose, for example, that the top of Mount Blanc is in latitude 45° 49′, and that its height is 2450 toises above the level of the sea. The point at which a line drawn from the top of this mountain, parallel to the earth's axis, will meet the superficies of the sea, (supposing that superficies continued inland from the Mediterranean), must be about 2382 toises in horizontal distance, or about 2-1/2 minutes south of the summit, that is, in the parallel of 45° 46-1/2′; and if this parallel be continued all round the globe, the points of the earth's surface between it and the equator, are all more distant from the earth's axis than the top of Mount Blanc is; whereas all the points to the north of it are nearer to that axis. A stone, therefore, from the top of Mount Blanc, if carried any where to the south of the above parallel, will retard the earth's diurnal motion; but if carried any where to the north of the same line, will accelerate that motion. The same quantity of matter, however, carried an equal distance toward the pole, and toward the equator, from any point, will lose more velocity in the former case than it will gain in the latter, as easily follows from the nature of circle. Therefore, supposing an equal dispersion of the detritus of a mountain in all directions, the parts that go toward the pole will most disturb the diurnal motion; and hence a balance on their side, or in favour of acceleration, as already observed.] 378. Mr Kirwan's second objection is founded on the misapprehension of a well-known fact in the natural history of the earth. "Rivers," says this author, "do not carry into the sea the spoils which they bring from the land, but employ them in the formation of deltas of low alluvial land at their mouths, according to what Major Rennell has proved." The fact of the formation of _deltas_ from the spoils which the rivers carry from the higher grounds, is perfectly ascertained; and the detail into which Major Rennell has entered in the passage referred to by Mr Kirwan, does credit to the acuteness and accuracy of that excellent geographer. But it is not there asserted, that rivers employ _all_ the materials which they carry with them, in the formation of those deltas, and deliver none of them into the sea. On the contrary, they carry from the _delta_ itself mud and earth, which they can deposit no where but in the sea; and it is this circumstance chiefly that limits the increase of those alluvial lands, and makes them either cease to increase, or makes them increase very slowly after a certain period, though the supply of earth from the higher grounds remains nearly the same. To make Mr Kirwan's argument conclusive, it would be necessary to prove, that _all_ the mud carried down by the Nile or the Ganges, was deposited on the low lands before these rivers enter the sea; a thing so obviously absurd, that nothing but his haste to obtain a conclusion unfavourable to the Plutonic system, could have