Abstract
American Journal of Science, September.—A post-Tertiary elevation of the Sierra Nevada, shown by the river-beds, by Joseph Le Conte. In further elucidation of his already published speculations regarding an upheaval of the Sierra Nevada towards the close of the Tertiary epoch, the author here brings forward much additional evidence, also correlating this movement with a contemporaneous elevation in other parts of the western half of the continent. He endeavours to show that the upward movement, which seems to have affected all high latitude regions at that time, but which was oscillatory and therefore temporary on the eastern side of North America and in Europe, on the Pacific slope was permanent, and has largely determined the orographic structure of that region.—The strain effect of sudden cooling, as exhibited by glass and by steel (second paper), by C. Barus and V. Strouhal. In their first communication the authors compared the strains experienced by glass and steel on sudden cooling, by aid of the density variations observed when the bodies carrying strain were annealed, as a whole. Here they seek to confirm their earlier inference relative to the temper-strain of glass. They also investigated the density-relations of consecutive similar shells of the Prince Rupert drop, and the optical character of the successive cores. In general it is shown that the optical effect of the temper-strain in glass may be regarded as the analogue of the electrical effect of the temper-strain in steel. In a further communication a more specific inquiry will be made into the causes of hardness itself, with a view to throwing some light on the mysterious transformations of carbon.—Devonian Lamellibranchiata and species-making, by Henry S. Williams. In connection with the publication of Prof. James Hall's monograph on Devonian Lamellibranchs, completing vol. v. part I of the “Palaeontology of New York,” it is pointed out that fossil species, and even genera, are unduly multiplied on totally inadequate data. Species and genera cannot be regarded as established so long as the author himself is unable to distribute the typical specimens, twice alike, without reference to the original labels.—Note on the composition of certain “Pliocene sandstones” from Montana and Idaho, by George P. Merrill. While lately classifying the rocks collected in Montana and Idaho by Dr. A. C. Peale in 1871, the author's attention was called to some fragments labelled as “Pliocene” sandstones. A glance, however, showed that they strongly resembled compacted volcanic dust and sand, and a microscopic examination made it evident that the stones consisted very largely of minute flakes of pumiceous glass sufficiently compacted to be readily broken out into hard specimens, but extremely friable. The specimens are fully described and some speculations offered as to their probable origin. It is added that in Kansas and Nebraska these dusts are collected and sold as diamond polishing powder, or used in the preparation of the so-called “geyserite” sconring-soap.—Contributions to mineralogy, by W. Earl Hidden, with crystallographic notes by A. Des Cloizeaux. The paper deals with the ipodumene, black tourmaline, xenotime, and twin crystals of monazite from North Carolina; a remarkable crystal of herderite found in 1884 near Stoneham, Maine; a twin crystal of molybdenite from Renfrew, Canada; and the phenacite from Florissant, El Paso County, Colorado.—Turquois from New Mexico, by F. W. Clarke and J. S. Diller. A full analysis and microscopic study is given of some specimens from the turquois mines of Los Cerillos, New Mexico, about 22 miles south-west of Santa Fé. The turquois-bearing rock appears to be eruptive, and probably of Tertiary age, while the small size of the veins and their limited distribution show that the turquois is of local origin, possibly the result of alteration of some other mineral.— On the electrical resistance of soft carbon under pressure, by T. C. Mendenhall. In reply to Prof. Sylvanus P. Thompson's objections, the author describes some fresh experiments fully confirming his views regarding the change in the resistance of carbon due to change of pressure. In the form of compressed lampblack the electrical resistance of carbon varies greatly with the pressure to which it is subjected, and the variation is mainly due to a real change in the resistance of the carbon itself.—:Comparison of maps of the ultra-violet spectrum, by Edward C. dickering. Prof. Rowland's recently published photograph of the solar spectrum is compared with Draper's map of the ultraviolet portion of the spectrum prepared in 1873, with which it is shown to agree very closely. The mean difference for the seventy-six lines compared was 0.012, corresponding to about 1/800 inch upon the Draper map. It may therefore be assumed that the probable error of a wave-length derived from this map will not exceed 1/100 unit if the correction here given be first applied.—On two hitherto undescribed meteoric stones, by Edward S. Dana and Samuel L. Penfield. One of these meteorites was found, in 1869, between Salt Lake City and Echo, Utah; the other, in 1846, near Cape Girardeau, South-West Missouri. Olivine is the most prominent constituent of the former, while the latter is a light gray chondrite.
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Scientific Serials . Nature 34, 539–540 (1886). https://doi.org/10.1038/034539a0
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DOI: https://doi.org/10.1038/034539a0