Scientific Serials

Abstract

Bulletin de l'Académie des Sciences de St. Pétersbourg, 5th series, t. ii. No. 4, April 1895.—Proceedings, in which we notice the discovery, by G. Schneider, in Prof. Kovalevsky's laboratory, of lymphatic glands in the earth-worm, Dendrolæna rubida (Crimea), and in Perichæta; as well as a communication by E. Burinsky, on his method of restoring by means of photography the writing in old documents which time has rendered invisible. A number of good negatives having been taken on collodion pellicules, they are superposed, and the visibility of the faintest markings is rendered still greater by means of a “contrast positive” obtained with regulated artificial light.—Definitive researches into the variations of latitude at Pulkova, on the ground of older observations made with the great vertical circle, by A. Ivanoff (in French). The previous memoirs of the author on the same subject being considered as first approximations only, the definitive formulae are now given. The observations of the years 1863–1875 and 1842–1849 are treated for that purpose separately. Both series lead to formulæ which agree very well with the formula given by Mr. Chandler in the Astronomical Journal, No. 322; however, the Pulkova observations of the first-named period seem to point to the necessity of slightly reducing the half-amplitude of the yearly term in Chandler's formula. Two long series of Pulkova observations thus fully confirm Mr. Chandler's conclusions.—On the measurements and calculations of some photographic charts of the stars, by F. Renz (in German). A catalogue of all stars, down to the magnitude 11˙0, which were occultated by the moon during the last eclipse, was given in the Astronomische Nachrichten. It appeared, however, that occultations of stars down to the twelfth magnitude could be observed at several observatories. Accordingly, the corresponding region of the sky was photographed by Prof. Donner with such an exposure (25 minutes) as to obtain the stars of twelfth magnitude as well, and F. Renz measured their positions with the Pulkova Repsold apparatus. The Potsdam photographs of the same region, made in 1891, were also re-measured, while the right ascensions of thirty-five fundamental stars were accurately determined at Pulkova with the meridian circle. The agreement between the different plates is quite satisfactory; and no distortion of the field could be detected. However, there are certain small systematic errors which cannot yet be well explained. Thus, the right ascensions on plate i. are on the average by 0˙047s. greater than the values deduced from plate ii.—The Arachnides collected by G. Potanin in Mongolia in 1876—1879, by E. Simon (in Latin). Part i. Aranæ and Opiliones; forty-one species are mentioned and described, nineteen being new species.—Do the spurs of the Carpathians penetrate into European Russia? by General A. Tillo (in Russian). The question is answered in the negative. Supan and Lehman, in Kirchhoff s “Länderkunde von Europa,” trace the limits of the Carpathians outside the boundaries of Russia; so also the Russian geologists, Barbot-de-Marnyand Karpinskiy, did not see continuations of these mountains either in Poland or in Russia. The new hypsometrical map, now compiled by the author on a larger scale (27 miles to the inch), confirms this view.—New or little known Ixodidae in the museum of the St. Petersburg Academy, by A. Birula (in Latin). Eight new species are described and figured on two plates.