rance of the land and fresh-water exuvia over those of marine origin, observable in these strata, warrants the conclusion that the Hastings beds were formed by a very different agent from that which effected the deposition of the Portland limestone below, and the sands and chalks above them. The seas in the primitive ages of our planet were inhabited by vast tribes of multilocular shells, which, however variable in their species, were not only of the same family, but also of the same genera, namely, Belemnites, Ammonites, and Nautilites. These shells, if we may draw any conclusions from our knowledge of the habits of the recent species of the only genus that still exists, were indisputably inhabitants of the ocean; and the presence of their remains in any considerable quantity in a stratum, affords a fair presumption that such stratum is a marine deposit. The converse of this proposition, we conceive, must hold good in a case like the present, where not a vestige of these ancient marine genera can be traced, among innumerable remains of terrestrial vegetables and animals, and of fresh-water testaceæ. The occasional occurrence of marine exuviæ affords no grounds for a contrary opinion, since this fact is no more than might be expected under such circumstances, and is in strict accordance with what may be observed in the deltas and estuaries of all great rivers. "We cannot leave this subject, without offering a few general remarks on the probable condition of the country through which the waters flowed that - deposited the strata of Tilgate Forest; and on the nature of its animal and vegetable productions. Whether it were an island or a continent, may not be determined; but that it was diversified by hill and valley, and enjoyed a climate of a higher temperature than any part of modern Europe, is more than probable. Several kinds of ferns appear to have constituted the immediate vegetable clothing of the soil; the elegant Hymenopteris psilotoides, which probably never attained a greater height than three or four feet, and the beautiful Pecopteris reticulata, of still lesser growth, being abundant every where. It is easy to conceive what would be the appearance of the valleys and plains covered with these plants, from that presented by modern tracts, where the common ferns so generally prevail. But the loftier vegetables were so entirely distinct from any that are now known to exist in European countries, that we seek in vain for any thing at all analogous without the Tropics. The forests of Clathrarie and Endogenite (the plants of which, like some of the recent arborescent ferns, probably attained a height of thirty or forty feet), must have borne a much greater resemblance to those of tropical regions, than to any that now occur in temperate climates. That the soil was of a sandy nature on the hills and less elevated parts of the country, and argillaceous in the plains and marshes, may be inferred from the vegetable remains, and from the nature of the substances in which they are inclosed. Sand and clay every where prevail in the Hastings strata; nor is it unworthy of remark, that the recent vegetables to which the fossil plants bear the greatest analogy, affect soils of this description. If we attempt to pourtray the animals of this ancient country, our description will partake more of the character of romance, than of a legitimate deduction from established facts. Turtles of various kinds must have been seen on the banks of its rivers or lakes, and groups of enormous crocodiles basking in the fens and shallows. "The gigantic Megalosaurus, and yet more gigantic Iguanodon, to whom the groves of palms and arborescent ferns would be mere beds of reeds, must have been of such prodigious magnitude, that the existing animal creation presents us with no fit objects of comparison. Imagine an animal of the lizard tribe, three or four times as large as the largest crocodile, having jaws equal in size to the incisors of the rhinoceros, and crested with horns; such a creature must have been the Iguanodon. Nor were the inhabitants of the waters much less wonderful; witness the Plesiosaurus, which only required wings to be a flying dragon; the fishes resembling Siluri, Balistæ," &c. . 3. Mathematical and Astronomical Tables for the use of Students of Mathematics, Practical Astronomers, Surveyors, Engineers, and Navigators. By WILLIAM GALBRAITH, M. A. Oliver & Boyd, Edinburgh. 9s.. THIS portable and cheap volume is well worthy of the attention of the practical men alluded to in the title page, and we have no doubt, that, when its merits come to be sufficiently known, it will supersede the use of every other with which we are acquainted. It is needless to mention, that Mr Galbraith gives all the ordinary tables to be found in works with similar objects, such as the logarithms of numbers, logarithmic sines and tangents, and others, without which no surveyor, seaman, or astronomer, can advance a step; and we shall confine ourselves in this notice to an enumeration of such additions and improvements as Mr Galbraith has made, and which we think claim for his work, as we have said above, the notice of all men who are really at work on such subjects. In the first place, we consider that Mr Galbraith has great merit for giving, in a clear, well ordered, and perfectly scientific style, such a course of demonstrative reasoning on the theory as well as the practice of his subject, as cannot fail to be very useful to students who have a real wish to understand what they are about, and whose better taste and judgment have heretofore been offended by these epitomes which, to use their slang phrase, have been reduced to the lowest capacity. The various methods of obtaining the longitude, are discussed at some length, and with singular clearness. We are not aware that in any other work of this elementary nature, those minute corrections in the lunar method are given; and, in fact, we suspect few navigators are aware of their importance. We allude to the equations for second differences in the distances, which are correctly given only for every 3 hours in the Nautical Almanac, but which are not found in strictness, for an intermediate period, by simple arithmetical proportion. This equation, in some cases, amounts to 6 seconds of distance, 12 seconds of time, or 3 minutes of longitude. Mr Galbraith has computed two little tables for obtaining the proper correction (Introduction, page 102.) Another small correction on account of the oblique semidiameter, is found in two tables by Dr Young, given at page 101. And a table is given by Mr Henderson of Edinburgh, for another correction still, namely, that arising from the effect on the horizontal parallax of the moon, caused by the oblate figure of the earth. We recommend Mr Galbraith, in his next edition, to bring all these corrections distinctly under the reader's view at one place. Our author does not confine himself, however, to the problems in ordinary use, such as lunar observations, occultations of the fixed stars, chronometrical observations, and the measurement of heights by the barometer, which last is admirably executed, but enters also with the full spirit of an observer, and all the minute accuracy of a computer, into the elegant disquisitions dependent upon the figure of the earth, the velocity of sound, and other topics of high interest. We shall now proceed to point out briefly those improvements and additions which we have been most struck with in the tables. In Table II. of the common logarithms, there are added proportional parts, which greatly facilitate its use. *Table V. or logarithmic tangents, &c. has two sets of arguments, one for time, and one for arc, besides proportional parts for seconds at the bottom. We are decidedly of opinion, however, that, for most practical purposes, it is infinitely better to have separate tables for converting time into arc, and the reverse; and we have reason to believe, accordingly, that Mr Galbraith stopped the press to give tables LXI. and LXII. at our suggestion. In the next edition we hope he will place these two tables by the side of XXX. and XXXI., for converting solar into siderial time, and the reverse, and near XXXII. for converting mean time into parts of the equator. These are all eminently useful; and we are glad to observe Mr Galbraith giving them at full length, to single seconds, and not in the usual abbreviated shape, which is very teazing. Tables VI. and VII., for natural sines, tangents, &c. are too contracted, being given to degrees only; if given at all they should be to minutes. it. Table IX., for taking out the proportional parts for daily dif ferences of declination, right ascension, &c. we do not much like; as it requires the use of the proportional logarithms in the next JANUARY-MARCH 1827. D d table. We approve more of the table of proportional logarithms to twenty-four hours by Lax and others, which gives the answer at one inspection. Tables XIII. gives the correction to be added to the sun's altitude, and combines the dip, refraction, parallax and semi-diameter. We confess, however, we prefer that these corrections should not be slumped together in this way, and have always made it a rule to teach our young friends to shun such tables, and take out each correction separately. Table XVI. has been re-computed, expressly for this work, from the sun's horizontal parallex taken at 8.768. Table XVII. gives Mr Ivory's refractions, but it has been considerably extended, and, as we think, improved, by having the refractions and their logarithms to every 10' from the zenith to the horizon. The addition of proportional parts to the three succeeding tables for the corrections due to the thermometer and barometer is very praiseworthy, as it materially facilitates their applica tion. We observe, that a column has been added to table XXVII. of Equations for second differences, by which they are adapted to the sun's declination; and although, in ordinary cases, no correction for the irregularity of the sun's motion is necessary, it does become of consequence in very accurate observations for Patitude made near the Solstices. Table LIX. gives the logarithms of the numbers in Rossel's well known table for correcting the longitudes determined by chronometer, when the rate has been found to have varied. Everything which contributes to the accuracy of such determinations is valuable; and we think Mr Galbraith, by dwelling so frequently on these minute corrections, does essential service to science, by making observers aware how easily and safely they may be taken into account. Table LXIII. contains, in a compendious shape, many extremely useful numbers, with their logarithms and comple ments. Tables LXVI. and LXVII, for the third and fourth differences of the moon's motion, are by Mr Henderson, a very ingenious mathematician in Edinburgh. The last table, for finding the latitude by the Polar Star, is by Captain Kater, and is sufficiently accurate for sea purposes. We agree, however, with that observer, in thinking the direct method the most satisfactory one. List of Patents granted in England, from 8th December 1826 to 16th January 1827. 1827, Dec. 8. To THOMAS MACHELL of Berners Street, Oxford Street, London, surgeon, for improvements on apparatus applicable to the burning of oil, &c. TO ROBERT DICKINSON of New Park Street, Southwark, for an invention for the formation, coating and covering of vessels or packages for containing, preserving, or conveying goods, whether liquid or solid, &c. 13. TO CHARLES PEARSON of Greenwich, Esq. RICHARD WILTY of Hanley, Staffordshire, engineer, and WILLIAM GILLMAN of Whitechapel, engineer, for a method of applying heat to certain useful purposes. TO CHARLES HARSLEBEN of Great Ormond Street, Esq. for his ma- TO JOHN COSTIGNI of Collon, in the county of Louth, civil engi- 18. TO WILLIAM JOHNSTON of Droitwich, for improvements in the TO MAURICE DE JOUGH of Warrington, cotton-spinner, for improvements in machinery or apparatus for preparing rovings, and for spinning and winding fibrous substances. 20. TO CHARLES HARSLEBEN, of Great Ormond Street, Esq. for improvements in building ships and other vessels, applicable to various purposes for propelling the same. TO THOMAS QUARRILL, of Peter's Hill, London, for improvements TO WILLIAM KINGSTON, master mill-wright, of Port Dock |