Page:Popular Science Monthly Volume 10.djvu/262

250 be carried to a distance by a few horizontal flues of large dimensions, terminating in lofty chimneys on a hillside or distant plain, as is done at the mercury-mines of Idria and some other places. With a little care in the arrangements, the smoke would be wholly deposited in the horizontal flues, and would be available for agricultural uses.

The Tomato-Plant as a Protection against Insects.—In a peach-orchard planted by M. Siroy, a member of the Valparaiso Society of Horticulture, the trees at first grew well and strongly. But, on commencing to bud, they were invaded by the curculio; and this insect was followed, as frequently happens, by ants. While the trees were thus infested, the idea occurred to M. Siroy that by placing leaves around the trunks and branches he might ward off the rays of the sun, which were very powerful. For this purpose he happened to choose tomato-leaves. On the following day he found the trees entirely free from their enemies, not one remaining, except here and there where a curled leaf prevented the tomato from exercising its influence. These leaves he carefully unrolled, placing upon them fresh ones from the tomato-vine, with the result of banishing the last insect, and enabling the trees to grow with luxuriance. Wishing to carry the experiment still further, he steeped in water some fresh leaves of the tomato, and sprinkled with this infusion other plants, roses and oranges. In two days these were also free from the innumerable insects which covered them.

The Age of Paleolithic Man.—Dr. R. H. Tiddeman contributes to Nature for October 5th a paper in which he reaffirms the inter-glacial age of paleolithic man and of the fauna with which he is associated. The position not only of human but of animal remains points clearly to the fact of their existence subsequent to a deposit of glacial drift, but previous to another deposit of similar material. The facts may be taken as part of the evidence which proves the disappearance of a great ice-sheet which covered Scotland, England, and portions of the Continent, and the return of it after a period of temperate climate during which man and animals inhabited the region.

The direct evidences of the inter-glacial age of paleolithic man from the actual infraposition of his bones or implements are stated as follows:

1. Victoria Cave, Settle: a human fibula under glacial till, and associated with bones of Elephas antiquus, Rhinoceros leptorhinus, hyena, hippopotamus, etc.

2. At Wetzikon, Canton Zürich, a piece of lignite containing basket-work lying beneath glacial deposits, and associated with Elephas antiquus and Rhinoceros leptorhinus.

3. Near Brandon, Suffolk, implements with bones not yet determined in brick earth beneath the great chalky bowlder clay of East Anglia.

Dr. Tiddeman says the "Settle till is undoubtedly of the age of the ice-sheet. The Wetzikon lignite lies upon a glacial till beneath a river-gravel on which are great erratic blocks clearly indicating the presence of a great glacier posterior in date to the organic remains. The Brandon implements are beneath the chalky bowlder clay."

Inequality of the Ocean-Bed.—In opening the Geographical Section of the British Association at Glasgow, Captain Evans said that it was learned for the first time by the Challenger's results—ably supplemented as they had recently been by the action of the United States Government in the Pacific, and by an admirable series of soundings made in the exploratory German ship-of-war Gazelle—that the unbroken range of ocean in the southern hemisphere was much shallower than the northern seas; that it had no features approaching in character those grand abysmal depths of 27,000 and 23,500 feet found respectively in the North Pacific and North Atlantic Oceans, as the greatest reliable depths recorded did not exceed 17,000 feet. The general surface of the seabed presented in general to the eye, when graphically rendered on charts by contour lines of equal soundings, extensive plateaux varied with the gentlest of undulations. There was one great feature common to all oceans, and which may have some significance in the consideration of ocean circulation, and as affecting the genesis and translation of the great tidal wave and other tidal