Page:Popular Science Monthly Volume 46.djvu/729

 Spencer, J. W. Reconstruction of the Antillean Continent. Rochester, N. Y.: Geological Society of America. Pp. 36.

Stone, Witmer. The Birds of Eastern Pennsylvania and New Jersey. Philadelphia: Academy of Natural Sciences. Pp. 185.

Tariff Laws of 18510 and 1894. Comparison of Text. Washington: Government Printing Office. Pp. 241.

Thompson, Sylvanus P. Elementary Lessons in Electricity and Magnetism. New Edition, revised throughout, with Additions. New York: Macmillan & Co. Pp. 628. $1.40.

Tolman, William H. History of Higher Education in Rhode Island. Washington: United States Bureau of Education. Pp. 208, with Plates.

Ward, C. Osborne. The Equilibration of Human Aptitudes, and Powers of Adaptation. Washington: National Watchman Company. Pp. 333. $1.25.

Ward, Lester F. Natural Storage of Energy. Washington. Pp. 12.

White, Theodore G. The Geology of Essex and Willsboro Townships, Essex County, N. Y. Contributions from the Geological Department of Columbia College. Pp. 14, with Plates.

 

Transportation of Dust in the Air.—In his studies of the atmospheric transportation of matter, Prof. J. A. Uddin finds that the velocities in the atmosphere being so much greater than those obtaining in rivers, lakes, and seas, the distances over which materials may be transported in it will be correspondingly greater, as was shown by the Krakatoa dust, of which the finer particles circled round the earth for months and even years. The greater depth of the aerial ocean renders it but little dependent in its movements on smaller elevations of the land. Few of our mountain ranges are so high as to stand materially in the way. "While the conditions requisite for much aërial erosion are limited to rather small areas of the land of the globe, there can be little doubt that deposition is much more general and widespread; for dust is carried everywhere, and if it be conceded that the atmosphere is never entirely free from dust, it follows that sedimentation occurs wherever and whenever there is a comparative calm. In places in the ocean where sedimentation is known to be very slow, atmospheric dust may be supposed to form an appreciable part of the deposits. The areas of deposition being much greater than the areas of erosion, it is evident that the accumulations of atmospheric sediments, as a rule, are insignificant, only exceptionally exceeding on the land the secular erosion by water, and therefore accumulating only in such exceptional cases. From a dynamical point of view the wind theory would appear to furnish an adequate explanation of the occurrence of the loess in the Mississippi Valley, at least as to most of its phases."

Habits of Polar Bears.—Appropriately to the recent mortal illness of the large polar bear in the London Zoölogical Gardens, a writer in the London Spectator remarks upon the mistake we make in supposing that the denizens of the frozen north necessarily suffer unduly in warmer climates, that "in all stories of arctic travel the extreme of cold appeals so strongly to the imagination that the heat of the nightless summer, in which the Eskimos strip themselves naked in their snow houses, is often forgotten. The good health and long life of the polar bears in this country [England] is less surprising than it at first appears when this extraordinary range of arctic temperature is remembered; moreover, the white bears are absolutely indifferent to fog and wet. Creatures that live and thrive on islands like Nova Zembla, where half their life is spent in fog and darkness, are little troubled by the London fog and damp of Regent's Park. . . . They will plunge and roll in the bath with as much pleasure in pouring rain or when the tank is full of clinking ice as on a hot summer day, and the only weather which seems to cause them discomfort is a hot August afternoon, when they pant and loll out their tongues like Newfoundland dogs." The size of these bears approaches that of the ox or the elephant, rather than that of the true carnivora. In some respects the bears' powers of movement exceed those of cats. They can maintain a gallop at a pace equal to that of a fast horse, leap wide gulfs with ease, swim fast enough to catch a salmon, and dive like a seal or an otter. They heartily enjoy their play, but are dangerous animals. No creatures are more carefully kept at arm's length by their keepers. Men who will rub their hands over a lion's face and eyes or pat the neck of a tiger, shift a bison bull across its stall like a bullock, or handle a python like a length of rope, would think it rash to put hand or limb within reach of these bears. . . . The fierceness of the polar bear is probably due to his enforced carnivorous diet. Every 