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    American Journal of Science, March.—Continuity of the glacial epoch, by G. F. Wright. In opposition to the author's view that the erosion of the rocky gorge of the Ohio river and its tributaries was preglacial, Prof. Chamberlin has maintained that the most important part of this rock erosion was interglacial. The author summarises the leading facts concerning the American glacial epoch by supposing that the earlier portions of the tertiary period were characterised by low altitude of land and warm temperature up to near the pole. A period of slow continental elevation of the regions which are now covered by glacial drift was in progress late in the pliocene epoch. During this stage the fiords of northern Europe and America and the extensive rocky gorges, like those of the upper Ohio and its tributaries, were eroded. Owing to this elevation glacial conditions characterised all the higher latitudes of North America and Western Europe. The glaciated area then began to sink until the land was, north of the great lakes at any rate, several hundred feet lower than it is now. The channels of the Allegheny, the Susquehanna, and the Delaware rivers were silted up by glacial débris, but were re-excavated by torrents of clear water during the re-elevation of the continent consequent upon the melting of some thousands of feet of ice. There were doubtless many oscillations of the ice-front both during the general advance and the general retreat of the ice-sheet, but there does not seem to be any evidence of oscillations of the front sufficient to break the proper continuity of the period.—Deformation of the Lundy Beach and birth of Lake Erie, by J. W. Spencer. The inferred rate of terrestrial deformation in the Niagara district being 1.25 feet a century, it appears that before Niagara Falls can have receded past the Devonian ridge near Buffalo, the drainage of the upper lakes will have been turned into the Mississippi valley, which may require 7000 or 8000 years.—Six and seven-day weather periods, by H. Helm Clayton. The observation of barometric minima reveals many of instances of six and seven-day periodicities lasting several weeks, and sufficiently striking to be easily recognised. In the case of successive individual storms, it was found that during an interval of about twenty-seven days, corresponding with a solar rotation, the storm tracts were found in groups, in each of which the cyclones all followed the same general direction, and were separated from each other by intervals of six or seven days, or in some cases by half these intervals.

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