Scientific Serials

Abstract

American Journal of Science, January.—Measurement of the Peruvian arc, by E. D. Preston. In this paper, which was read before the American Association for the Advancement of Science at Toronto, August 1889, the author reviews the whole question of the relative lengths of the earth's axes, dealing in detail with Bouguer's expedition to Peru in 1735, and arguing that the amplitude of his Peruvian arc may be in error by many seconds. Hence he contends that the geodetic science of to-day demands the remeasurement of this arc.—Neutralization of induction, by John Trowbridge and Samuel Sheldon. A system of neutralization for inductive disturbances is here described, which might be adopted where it is impossible to employ entire metallic circuits in which the earth plays no part.—Divergent evolution and the Darwinian theory, by Rev. John T. Gulick. The author discusses Darwin's apparently contradictory views on the causes of natural selection on the one hand, and on the other on the causes of diversity of natural selection. He concludes that, though Darwin has not recognized segregation as a necessary condition of divergence of species, he has indicated one process (geographical or local separation under different environments) by which segregation is produced in nature, adding, however, that this is not the only cause of segregation and consequent divergence.—The Devonian system of North and South Devonshire, by H. S. Williams. During a recent visit to England the author studied this system both on the spot and in the geological collections in London and elsewhere. He dwells especially, (1) on the close resemblance of the English Devonian species to those of the New York Devonian, though mostly passing under different names, and (2) on the character of the North and South Devonian rocks, which in appearance, composition, and order are as different as two distinct systems well can be.—The zinciferous clays of South-West Missouri, and a theory as to the growth of the calamine of that section, by W. H. Seamon. Full analyses are given of the so-called “tallow” and “joint” clays occurring associated and sometimes intermixed in every calamine digging in South-West Missouri. These analyses show a large percentage, often from 50 to 56, of zinc oxide, and it is inferred that at one time all the massive calamine probably existed in “tallow clays” precipitated from solutions.—On the spectrum of ζ Ursæ Majoris, by Edward C. Pickering.—Origin of normal faults, by T. Mellard Reade. Some critical remarks are offered on Prof. Le Conte's recent explanation of the origin of normal faults, which is not new, and presents many insuperable difficulties.—Papers were submitted by J. Dawson Hawkins, on a specimen of minium from Leadville; by William P. Blake, on some minerals from Arizona; by F. A. Genth, on a new occurrence of corundum in Patrick County, Virginia; by Alfred C. Lane, on the estimation of the optical angle of observations in parallel light; by L. G. Eakins, on a new stone meteorite from Texas; by Edward S. Dana, on the barium sulphate from Perkin's Mill, Templeton, Province of Quebec; and by O. C. Marsh, on some new Dinosaurian reptiles recently discovered in Wyoming, Colorado, and Dakota.