Page:Popular Science Monthly Volume 25.djvu/732

716 adorn their nests, and by instances in which their choice of companions, food-fruits, etc., is guided by color. Many of the feathered tribes also "manifest real pleasure at the execution of simple harmonies. They enjoy the notes of musical instruments, but more especially their own songs and those of one another. . . . Our unmusical English sparrow enjoys the songs of other birds; on different occasions I have seen several of them gather about a robin as he caroled a pleasant song; when they came too near or in too large numbers, he would dart at them and drive them out of the tree, but when he commenced again to sing some of them were quite sure to return. A friend sends me an account of a bobolink, that placed in a cage with some canaries exhibited great delight at their songs. He did not sing himself, but with a peculiar cluck could always set the canaries singing. After a while he began to learn their songs, note by note, and in the course of a few weeks mastered the entire song." The goose is also fond of music, "and a lively air on a violin will sometimes set a whole flock wild with delight. On one occasion, at a country wedding, I was witness of a curious performance by one of these animals. After dinner a lady entertained the guests assembled on the lawn with music from an accordeon. A flock of geese were feeding in the road just below the house, and with outstretched necks answered back loud notes of satisfaction. Soon a white gander commenced dancing a lively jig, keeping good time to the music. For several minutes he kept up the performance, to the great delight of the company. The experiment was tried several times for a week or more, and the tones of the accordeon never failed to set the old gander into a lively dance."

Milne-Edwards's Marine Investigations.—M. Alphonse Milne-Edwards has expressed himself well satisfied with the results of his deep-sea expedition in the Talisman. He claims to have corrected some of the soundings as given in a recent German atlas, and to have traced a different relief from the one indicated in it for the ocean-bed. He found the bottom of the Sargasso Sea—six thousand metres deep—to be of a volcanic character. Some of the lavas and scoriæ in the collection the expedition has brought home seem to be of relatively recent origin, and to offer an explanation of the poverty of the flora of the region in which they were found. In a letter to the French Geographical Society, M. Milne-Edwards speaks of an immense volcanic bed running parallel with the Andes, of which the Cape Verde Islands, the Canaries, and the Azores form the culminating peaks, and which, he conjectures, may extend to Iceland.

The Glacial Dam and Lake of the Ohio River.—Professor G. Frederick Wright, in tracing the boundary-line of the glaciated area through Ohio, found that it crossed over into Kentucky in the neighborhood of Cincinnati, returning, however, to the north side of the Ohio River at a few miles farther down. Examining the ground more closely, he found that the entire valley of the river, for a distance of fifty miles in this region, had been, for a short time during the glacial period, filled with glacial matter which formed a dam at least five hundred and fifty feet high. The effect of this must necessarily have been to make a narrow lake corresponding in depth with the ice-barrier, and extending far up the Ohio and its tributaries, including the Licking in Kentucky, the Kanawha in West Virginia, and the Alleghany and Monongahela in Pennsylvania, and covering the present site of Pittsburg to a depth of about three hundred feet. Evidence of the former existence of such a lake, in the shape of terraces marking its margin, has been found along these rivers, in one case independently of Professor Wright's investigations. Professor J. C. White, of Morgantown, West Virginia, and of the Pennsylvania Geological Survey, says that it is exactly what is needed to explain the terraces along the Monongahela, which extend from Pittsburg as far south at least as Fairmount, West Virginia, one hundred and thirty miles, and "suddenly disappear at an elevation of one thousand and fifty or one thousand and seventy-five feet above tide, or about two hundred and seventy-five feet above the river." Professor Lesley has observed terraces along the Alleghany and its tributaries, at the same absolute level. Along the Great Kanawha, water-worn bowlder deposits disappear at an elevation of from two