But what is the evidence of the deposits formed at this period? Here we meet with results most diverse and contradictory, but I think there can be little doubt that on this kind of evidence the time required for the Post-glacial period has been greatly exaggerated, especially by those geologists who refuse to receive such views as to subsidence and elevation as those above stated. The calculations of long time based on the gravels of the Somme, on the cone of the Tinière, on the peat bogs of France and Denmark, on certain cavern deposits, have all been shown to be more or less at fault; and possibly none of these reach further back then the six or seven thousand years which, according to Dr. Andrews, have elapsed since the close of the boulder-clay deposits in America.[AN] I am aware that such a statement will be regarded with surprise by many in England, where even the popular literature has been penetrated with the idea of a duration of the human period immensely long in comparison with what used to be the popular belief; but I feel convinced that the scientific pendulum must swing backward in this direction nearer to its old position. Let us look at a few of the facts. Much use has been made of the "cone" or delta of the Tinière on the eastern side of the Lake of Geneva, as an illustration of the duration of the Modern period. This little stream has deposited at its mouth a mass of _débris_ carried down from the hills. This being cut through by a railway, is found to contain Roman remains to a depth of four feet, bronze implements to a depth of ten feet, stone implements at a depth of nineteen feet. The deposit ceased about three hundred years ago, and calculating 1300 to 1500 years for the Roman period, we should have 7000 to 10,000 years as the age of the cone. But before the formation of the present cone, another had been formed twelve times as large. Thus for the two cones together, a duration of more then 90,000 years is claimed. It appears, however, that this calculation has been made irrespective of two essential elements in the question. No allowance has been made for the fact that the inner layers of a cone are necessarily smaller then the outer; nor for the further fact that the older cone belongs to a distinct time (the pluvial age already referred to), when the rainfall was much larger, and the transporting power of the torrent great in proportion. Making allowance for these conditions, the age of the newer cone, that holding human remains, falls between 4000 and 5000 years. The peat bed of Abbeville, in the north of France, has grown at the rate of one and a half to two inches in a century. Being twenty-six feet in thickness, the time occupied in its growth must have amounted to 20,000 years; and yet it is probably newer then some of the gravels on the same river containing flint implements. But the composition of the Abbeville peat shows that it's a forest peat, and the erect stems