The conditions, indeed, which are necessary to ensure a load for the carrying ice, such as proximity to the rocks the detached fragments of which are to rest on its surface, are more peculiarly present in ice formed under or brought into contact with precipitous rocky banks, and in that formed in deep narrow gulfs--in short, in ice constituted after the manner of glaciers. A large portion, therefore, of field ice must necessarily float about unencumbered with rubbish or fragments of rocks. Boethlingk, in treating on the diluvial and alluvial formations of South Finland, incidentally touches upon this subject. “The dispersion,” he observes, “of these blocks, is very probably in accordance with a phenomenon which may be observed on many seas and rivers, and which depends on the presence of blocks of stone near the shore. Through what force and in what manner the deposition of large blocks on the surface of all those formations which are at the water’s brink even now happens, can be observed every spring, by any one who, at the breaking up of the ice, repairs to those parts of the coast where the shore bears testimony, by the numerous blocks heaped up one upon the other, of their forcible deposition. Near Kiwinjemei, on the Wwoxen, there is, as it were, a wall nine feet high, stretching along the flat shore, composed of blocks of stone which have been gradually raised by the masses of ice. In several places such stones, three feet in diameter, were lying on flakes of ice, which, pressing onwards to the shore, had been shoved one over the other to the height of six or eight feet; so that no one could doubt the fact that the ice-flakes had been the carriers of the stones; and also, where the steepness of the ground permits the near approach of ice-shoals to the shore, that the blocks would be heaped up one over the other into a terrace or wall; whilst, on the contrary, on shallow coasts they would be scattered in the water, at a distance from the shore. The deposition of blocks depends therefore on the shore being accessible to ice-shoals driven in by winds or currents. Small blocks, also, are often cemented together by ice when the water over shallows, the bottoms of which are covered with loose stones, freezes; and when the water rises in the spring, or in consequence of storms setting in from the sea, the ice also rises, and with it the encased stones; and being driven out to sea, the stones, by the melting of the icy cement, are dropped in various places. In this way it is very probable that the boulders which lie scattered over the surface of the countries south of the Baltic were transported from Scandinavia and Finland on ice-shoals, at a time when the East Sea yet spread over those regions. Banks also are thrown up along the shore by the ice; they are never composed of large stones, but on flat sandy shores principally of sand.