and designated in England as the millstone-grit, is wanting in Ireland. N. B. This peculiar application of the term millstone-grit is bad as a distinction, since a similar compound is generally found in beds in the fundamental or old red sandstone, and in some countries also frequently interstratified with the coal measures, e. g. in Germany. 2. A base of old red sandstone, supporting limestone, which alternates with sandstone, à considerable bed of the latter, with conglomerate, forming the immediate foundation of the coal measures, which are distinct; e. g. the Gloucestershire south coal basin. N. B. The more common coal bearing measures are in this basin separated into a lower and an upper series by an intervening thick bed of reddish sandstone, locally known by the name of Pennant-stone. N. B. A similar occurrence, on a larger or smaller scale, is not uncommon in Germany, and when the red sandstone thus occurs immediately under the magnesian or alpine limestone (with its calcareous or new conglomerate, the weissliegende), it is known by the name of todte liegende, or rothe liegende, or rothe todte liegende, in the same manner as these terms are applied to the fundamental red sandstone when also directly covered by the calcareous conglomerate and magnesian limestone. But the term rothe todte liegende has also been often erroneously applied, as already noticed above, to the calcareous or new conglomerate itself.* 3. A base of old red sandstone, supporting and alternating with some beds of limestone, succeeded by a coal formation, composed, in an ascending order, as follows: a. Of coal measures alternating with limestone, and with reddish sandstone, the coal being inconsiderable in quantity. b. Productive coal measures, alternating with numerous beds of limestone. * M. von Humboldt correctly distinguishes the weissliegende, as the bed which intervenes between the coal formation and the zechstein, or magnesian limestone (see p. 224 of the Essai). It thus corresponds with the calcareo-magnesian, or new conglomerate of England, appearing as its only representative. On the other hand, however, both M. von Humboldt and Dr. Boué speak of the zechstein, or magnesian limestone, as occurring sometimes interstratified with the coal measures. This is a position utterly at variance with all experience in the British Isles, and seems quite untenable, if we consider that the calcareous conglomerate, or weissliegende, is commonly found in an unconformable position, overlying both the coal measures, and the carboniferous series in general; being the first member of a new series; namely, of the gypseo-saliferous. In the instance quoted, e. g. in Lower Silesia (p. 34, 213, &c.) it is true that, in the year 1802, M. von Buch considered the limestone in question as zechstein, and as such as of an origin posterior to, and placed above the coal formation; but M. von Raumer in 1819 clearly showed that this limestone was repeatedly interstratified with the coal measures, and therefore not zechstein; and certainly no two series can be generally more distinct from each other than the carboniferous and the gypseo-saliferous series. Other instances cited, probably rest upon no securer foundation than misconception, or fallacious description. c. Coal measures, abundant in coal, but free from limestone. E. g. in the Scotch great coal tract. 4. A base of old red sandstone, supporting limestone, which not only constitutes the foundation of the coal formation, but alternates with the coal measures, often forming the immediate roof of the coal seams: e. g. the Glane coal basin, described above. 5. A. base of the same old red sandstone, supporting a coal formation, composed, in an ascending order: a. Of productive coal measures alternating with beds of sandstone conglomerate. b. Of coal measures alternating with limestone. E. g. the Sarre coal basin, described above. N. B. The coal measures of this basin are overlaid on the W and S by the new red or saliferous sandstone; so that if the series of coal measures be continued in that direction, and toward which they dip, they are withdrawn from observation. Could we follow them, it appears not improbable that the succeeding coal measures might be found free from limestone. But be this as it may, it is remarkable that in this coal field, the greatest number of the coal seams are found above the fundamental red sandstone, and beneath the limestone bearing strata, being thus directly connected with the former. The carboniferous series of all countries, whose members are complete, will probably be found referable to one or other of the preceding modes of association. In addition to those which relate to the alternation of the carboniferous limestone with the coal measures, may be cited analogous appearances in Silesia and Hungary, as described by MM. von Raumer and Beudant. The New Continent also presents, it seems, similar relations; e. g. in the coal formation of the Ohio, in the great basin of the Mississippi, where coal seams are represented as occurring both above and beneath the limestone.* The preceding examples refer to tracts where all the members of the series are present; but in some districts, the carboniferous limestone is found altogether wanting, the coal formation being directly connected with the old red sandstone; while in others, both the limestone and old red sandstone being absent, a simple coal formation is only met with. But in all cases, the series, whether complete or incomplete, reposes either on transition, or on primary tracts, or on both of these conjointly. The occasional association of trappean, amygdaloidal, and porphyritic rocks, both separately with the individual members, and conjointly with the series in general, is now too well known to require more than the simple notice of the fact. See the Account of an Expedition from Pittsburg to the Rocky Mountains in 1819 and 1820, by Edwin James, Botanist and Geologist to the Expedition. London, 1823. 0 4 11.17 0 58 2.66 ART. IV. Corrections in Right Ascension of 37 Stars of the Green wich Catalogue. By James South, FRS. Mean AR h. m. s. b. m. s. 1824. a Arietis Rigel h. m. s. 1 57 16 42 2 53 544 4 25 50-01 5 3 42-21 5 6 5 11 B Tauri a Orionis h. m. s. h. m. s. 5 15 10 525 45 38-93 July 1+ 2.79" + 3.27"+2·33′′ + 1·92′′ + 1·76" + 2·00′′ + 1·24" + 1·81" + 1·47′′ |