The following Donations to the Library were announced: The Quarterly Journal of the Chemical Society. No. 4. 8vo. By the Society. Railway Economy: An Exposition of the advantages of Locomo tion by Locomotive Carriages, instead of the present expensive Transactions of the Royal Scottish Society of Arts. Monday, 5th February 1849. Vol. III., Sir T. MAKDOUGALL BRISBANE, Bart., President, in the Chair. The following communications were read: 1. On some peculiar Impressions on the Surface of certain Strata of Greywacké Schist, at Goldielands, in Roxburghshire. By James Elliot. Communicated by David Milne, Esq. tures. After some prefatory remarks on the general character of the greywacké formations in the south of Scotland, on their entire destitution of organic remains, or even decided impressions, and on the general prevalence of marks, produced apparently by shallow water, a singular series of schistose strata is described, of little more than two feet in thickness altogether, presenting everywhere peculiar feaFirst, there are two opposed surfaces, the one sprinkled over with thin, short, raised streaks, and the other with small cylindrical grains, all lying perfectly parallel to each other, and consisting of a hard substance, differing from the material and colour of the greywacké rocks. Next, there are a few seams of fine schist, and then a surface, covered with minute, sharply-defined indentations, having every one a lip turned up on one side, and sometimes clinging to the lip, a small speck of the same hard brown substance, which appears on the two surfaces first mentioned. The lips are invariably on the same side of the indentations, giving the surface the appearance of a farrier's rasp; and the uniform direction in which the lips are thrown out from the indentations, is exactly parallel to the streaks and grains first described. At right angles to that direction are narrow undulating ridges, such as would be produced by a cutting wind on a tenacious surface. The marks are preserved by a very thin coating of fine earth, and the opposite surface is not a counter-impression, but has peculiarities of its own. After the intervention of a few other seams, there follow repetitions of those already described, but somewhat varied. In conclusion, an explanation of all the appearances is attempted. The author suggests that they have been caused by showers of sand, driven by a strong wind upon the surface of the rocks before they had become hardened. The sand, he supposes, has been derived from volcanoes in activity at the period, and the existence of which is inferred by the igneous character of many of the neighbouring hills. 2. On the Causes of Local Peculiarities of Temperature in different parts of Great Britain. By James Elliot. Communicated by David Milne, Esq. Many remarkable diversities of temperature are observed in this island, which have not yet been satisfactorily accounted for, either by difference of latitude or of elevation, by shelter or exposure, or by the influence of currents in the ocean. It is attempted to shew that other causes usually assigned have no validity,—that the proximity of high, and consequently cold mountains, has no effect in cooling the low ground near them, even when their summits are covered with perpetual snow, and that a difference in the clearness of the sky, or in the radiating power of the surface of the ground, produces no effect on the average temperature. The great cause, then, of the diversities in question is to be found, the writer considers, in the latent heat of vapour,-in the caloric disengaged by its condensation, or absorbed in its formation. He shews the great addition which may be made to the temperature of the atmosphere by a heavy fall of snow to the windward, and, on the other. hand, the great loss of temperature by evaporation. The differences, in the amount of rain, he attributes almost entirely to the general slope of the surface over which the wind passes, in connexion with the height of the ground over which it has previously passed, and the differences of evaporation to the material of the soil and its covering, and to its state of drainage, natural or artificial. Some experiments are then detailed, shewing the amount of moisture capable of being retained by various coverings of soil, moss, &c., and the extent to which some of these promote evaporation. The writer con cludes by shewing the great improvement which may be made in the general climate of this island, and particularly in that of its mountainous districts, by complete draining. 3. Verbal Notices. By Dr Fleming. 1. On the Shell referred to by Ure in his "History of Rutherglen and Kilbride," as "a species of Patella."-Dr Fleming called the attention of the Society to the extraordinary merits of Mr Ure, who died in 1798, leaving a memorial, in the work above referred to, and which was published at Glasgow in 1793, of an acquaintance with organic remains unequalled on the part of any contemporary author of the United Kingdom. This work, however, is very seldom referred to by modern palæontologists, although eminently useful in illustrating the progress of discovery. It was likewise stated, that an additional degree of interest must be felt by the members of the Society, in consequence of a collection of organic remains, chiefly marine, and from the carboniferous limestone, which belonged to Mr Ure, having been presented by Mr Stark, and which now occupies a place in the cases up stairs. Dr Fleming stated, that the description of the Patella, referred to at p. 305, and delineated in Tab. xv., figs. 9, 10, is so obscure, doubtless in consequence of the imperfect specimen then in Ure's possession, that it was not until he had succeeded in procuring examples in nearly the same condition, along with others more characteristic, that he could refer the organism to its type, or, rather to the genus DISCINA of Lamarck. This genus was unaccountably confounded with Orbicula of Lamarck, by Mr G. B. Sowerby, in a paper in the thirteenth vol. of Linn. Trans., 465, and the errors there introduced have been propagated in the "Silurian System" of Murchison; the "Geology of Yorkshire," by Phillips; and the "Geological Report on Londonderry," &c., by Portlock. The species indicated for the first time by Ure, is probably referable to the Orbicula rugata of the Silurian System, p. 610, T. v., f. 11, although much doubt must rest on the determination. The shell consists of several somewhat easily separable layers. The external one, cuticle-like, exhibits regular concentric grooves, constituting the character of the O. rugata, while in the different aspects of the inferior layers, may be contemplated the O. nitida of Phillips, and the 0. striata of Sowerby. At the period when Ure wrote he seems to have been in possession of only imperfect examples, or the upper valve of this BRACHIOPOD, but in his col lection now on the table there are good specimens of the lower valve, as well as characteristically-marked upper ones. 2. On the "Fossil Echini" of Ure.-Dr Fleming stated, that having found plates of Ure's Echinus in company with fragments of spines, with proximal extremities, similar to the figure, Tab. xvi., f. 8, and the distal denticulated extremities conjoined, he had characterised the species in his "British Animals," denominating it CIDARIS Urii, thereby commemorating the labours of the discoverer. Captain Portlock, in the work already reported, has described and figured portions of, apparently, the same species, as CIDARIS Benburbensis, manufacturing new species besides, without being aware of the differences in the form of the spines, as well as in the sculpture of the plates, from different parts of the crust; truths illustrated by the existing British CIDARIS papillata, giving evidence to the palæontologist of the expediency of combining a knowledge of recent with extinct forms. Dr Fleming concluded this notice with stating that he found, during last autumn, the remains of this carboniferous limestone organism in the lowest bed of the old red sandstone series, on the Berwickshire coast, in which he detected marine remains, beginning at the fundamental conglomerate, where it rests on the “Transition Rocks" at the Siccart Point, and proceeding westward to Dunbar. 4. Notice by Professor Piazzi Smyth of Locke's Electric Observing Clock. This instrument, which has been invented in America, consists of an electro-magnetic machine, which, being placed in connection with an ordinary astronomical clock, does not interfere with the regularity of its going, while it marks the instant of each vibration of the pendulum on a revolving cylinder, whose circumference moves at the rate of one inch per second. Two wires being then taken to an observer at any distance, if he, when he observes a star crossing the meridianwire of his telescope, makes contact with the wires, that moment is immediately marked on the same moving cylinder where the even seconds are registered. The fraction of a second may be then obtained with as much accuracy as the space of an inch may be subdivided by ordinary mechanical means: say to the hundredth of a second. This method is further available in many cases where the present mode of noting transits is not, and admits of a great multiplication of observations during the short space of time that the star occupies in crossing the field of view. Sir T. MAKDOUGALL BRISBANE, Bart., President, in the Chair. The following Donations to the Library were announced:-Abhandlungen der Mathematisch-Physikalischen Classe der K. Bayerischen Akademie der Wissenschaften. Bde. I., II, III., & IV., Abtheil. 1 & 2. 4to. Abhandlungen der Philosophisch-Philologischen Classe der K. Denkrede auf Joseph Gerhard Zaccarini. Von Carl F. P. v. Martins. 4to. Rede bei eröffnung der Sizung der K. Bayerischen Akademie der Wissenschaften am 28 Marz 1848. Von Carl F. P. v. Martins. 4to.-By the Academy. Bulletin de la Société de Géographie. Tom. IX., 3me Série. 8vo. -By the Society. Journal of the London Geographical Society. Vol. XVIII., Part 2. 8vo. By the Society. Transactions of the China Branch of the Royal Asiatic Society. 1847. 8vo. By the Society. The American Journal of Science and Arts. 2d Series. Vol. VI., No. 18. 8vo.-By the Editors. The Quarterly Journal of the Geological Society. No. 16. 8vo. -By the Society. VOL. II. U |