And this conception is justified by the _aspect_ of the glacier. Thus, of the Glacier du Géant, Professor Tyndall says:--“It stretches smoothly for a long distance, then becomes disturbed, and then changes to a great frozen cascade, down which the ice appears to tumble in wild confusion. Above the cascade you see an expanse of shining snow, occupying an area of some square miles.” But we shall see that here, as in the world of man, appearances are deceitful, and that the glacier well deserves to be called an ice-river, in allusion to its regular and continuous motion. Between the snow-fall in the higher regions of the globe, and the quantity of snow which every summer disappears through liquefaction, the difference is very considerable. The supply, so to speak, exceeds the demand, and a residuum is annually left. It is only below the perpetual snow-line that the snow created and accumulated in winter is wholly melted in the warm season. And, therefore, if for any considerable period the excess upon any particular mountain continued to accumulate, immense masses of ice would gradually rise to the extreme height in the atmosphere affected by aqueous phenomena. Rendu, the Roman Catholic prelate, who first led the way to the discovery of the true nature of glaciers, says, very justly,--“The economy of the world would be soon destroyed, if at certain points accumulations of matter prevailed. The centre of gravity of the globe would be insensibly displaced, and the admirable regularity of its movements would be succeeded by disorder and perturbation. If the Poles did not send back to the Equatorial seas the waters which, reduced into vapour, issue daily from these burning regions, to be converted into ice in the Arctic and Antarctic Zones, ocean would be drained dry, and life would cease, as well as water, to circulate throughout our world. The Creator, however, in order to ensure the permanence of His almighty work, has called into existence the vast and powerful law of circulation, and this law the careful observer sees reproduced in all the economy of Nature. The water circulates from the ocean into the air, from the air it spreads over the earth, and from the earth it passes into the seas. The rivers return from whence they came, in order that they may issue forth anew; the air circulates around the globe, and, as it were, upon itself, passing and repassing successively at all the altitudes of the atmospheric column. The elements of every organic substance circulates in changing from the solid to the liquid or aëriform state, and in returning from the latter to the state of solidity or organization. It is not improbable that the universal agent which we designate under the name of fire, light, electricity, and magnetism, has probably also a circle of _circulation_ as extensive as the universe. Should its movements ever be known to us more than they now are, it is probable that they would afford the