to surrender it to the officials on the payment of about three halfpence for every pound weight, and will receive in return a card, on giving up which at the end of the journey the luggage will be re-delivered him. This insurance is to the value of a dollar a pound, by paying double, a double insurance may be effected. It is supposed that few persons will prefer to "take their chance," amidst the inevitable confusion arising from the simultaneous progress of four hundred passengers.

More Rings of Saturn.-Among the other evils of our foggy climate, must for the future be enumerated, one to which much attention has not hitherto been given-its inaptitude for astronomical observations. Signor Decuppis, of the Observatory at Rome, in a recent communication to the Academy of Sciences at Paris, gave an account of the results of some late observations in Saturn, which place this fact beyond a doubt. It was thought for a long time that Saturn possessed only one ring-it was not till Herschel brought into exercise the powers of his gigantic telescope that it was discovered to possess two. In the pure atmosphere of Rome,with the assistance of a powerful telescope, it was discovered on the 17th of June last, that the number amounted to four-and oa the 18th of June, Signor Decuppis, to his astonishment, clearly made out five. Having read with how much di iculty Herschel ascertained the existence of the smaller three of the seven satellites of the saine planet, the Roman astronomers were amazed to find, that to them they appeared with the greatest distinctness and brilliancy. With such a climate as theirs, it is no wonder that the Italians should be able to claim the discovery of an asteriod by Piazzi of Palernio, but it reflects no honour on them as cultivators of science, that the others should have been introduced to the world of science by Harding and Olbers and that the only planet added to the solar system should have been first detected on the South Parade in Bath.

South Eastern and Dover Railway.-We have paid our periodical visit to the works of this railway, to mark their progress. Our readers are aware that the galleries and shafts of the important tunnel at Shakespeare's Cliff are already complete, and we have now to notice that the two headways are progressing most satisfactorily. The chalk hitherto excavated is of extraordinary firm. ness, and fully realizes the expectation of the engineer.-that the roof of the tunnel will in no part require any extraneous support beyond the natural chalk. About four weeks hence, should the working continue favourable as hitherto, we may congratulate our readers upon the possibility of walking through the bowels of this noted cliff. The cuttings beyond are proceeding rapidly, and still further, the second tunnel has been commenced under very favourable appearances.-Dover Chron. Proposed Railway from London to the North.A new line of railway has just been projected, to be called the North Trunk Railway. It is proposed to commence at Islington, passing from thence between Highgate and Hampstead, by Finchley, Barnet, St. Alban's and Bedford, between Higham Ferrars and Wellingborough, and thence to Leicester, there to join the Midland Railway. This route would form a portion of a direct line from London to Edinburgh.

Newcastle and North Shields Railway.-Not

withstanding the very wet and untoward state of the autumn, the various works on the Newcastle and North Shields Railway are progressing favour. ably. We understand that the Company intend to apply to Parliament, in the ensuing session, for a renewed extension of their line to Tynemouth, and should they succeed in their praiseworthy undertaking, it cannot fail to be one of the most useful railways in the United Kingdom; it will be the means of opening out to the public, at a cheap rate, one of the best bathing stations on the eastern coast of England. As far as we can learn, the Company mean to carry their line through the town of North Shields by means of a tunnel similar to the one now in use under the town of Liverpool; by this arrangement the present features of the town will be perfectly preserved; and, in order to ac commodate the inhabitants, it is proposed by the Company that the locomotive engines shall stop short at the entrance of North Shields, and the trains to be thence forwarded through the tunnel to Tynemouth by horses every half hour, or oftener, if required.

Danube and Maine Canal.-The canal to counect the Danube and the Maine, recently commenced was not a favourite speculation in Germany, It was alleged that the country it was to cross was so sandy, that water would only be attainable at an enormous expense, or not at all, and that the canal would, in consequence, be at a stand still in summer. To the astonishment of every body, the engineers of the canal included, water has turned out uncommonly plentiful in the midst of the sandthat portion of the bed of the canal already completed is partly filled with water on the voluntary system; and it is found that some brooks, whose course it was in contemplation to divert, will not be wanted at all.

Birmingham Railroad.-Return between the 2nd October and 5th November inclusive, to and from Birmingham:-Travelled, 3,553,061 miles. Number of persons, 56,816. Duty paid to Government, £1,850 11s. The foregoing is the substance of the declaration of the Return made before the magistrates, Mr. Twyford, and Dr. Robinson, a county magistrate.

Bottle Washing Machine Premium.—In answer to numerous inquiries respecting the bottle washing premium, we beg to say, that we are in communication with the firm on whose behalf the prize was offered, and expect to be able to announce the award of the prize in a week or two.

Metropolitan Railway Map.-On the 1st of December will be published vol. xxix of the Mechanics' Magazine, price 9s., illustrated with a Railway Map of the Metropolis, taking in a radius of 15 miles from the Post-office. Encouraged by the extensive sale which our Railway Map of England has commanded, the Metropolitan Railway Map has been executed at a very great cost; the utmost exactness has been observed in reducing it from the Ordnance maps, and all the railways projected, up to the day of publication, have been distinctly and accurately marked from actual survey. The limits of the twopenny and threepenny post deliveries are also shown in the Map. The Metropolitan Railway Map alone, stitched in a wrapper, price 6d., and on fine paper, coloured, 18.

The Railway Map of England and Wales continues on sale, in a neat wrapper, price 6d.; and on fine paper, coloured, price is.

PISTRUCCI'S IMPROVED BANKER FOR SCULPTORS.

Sir,-The splendid talents of Mr. Pistrucci, Chief Medallist of her Majesty's Royal Mint, as a cameo-gem engraver" (as he has sometimes disparagingly been called), are pretty generally known, and almost universally admitted. His cameos have long been considered scarcely inferior to the best of the antique; and have frequently been mistaken, by some of the most approved judges, for ancient productions. Of his superior excellence as a medallist we have had several recent proofs afforded; but it is not generally known, that to first-rate artistical skill, he adds mechanical abilities of a very high order. Ten years ago he invented, and has since sent to Mexico, a very powerful coiningpress of wrought iron, which some of the first manufacturers in Birmingham are now beginning to appreciate and to copy.

Mr. Pistrucci is well known, by every person in the royal mint, to be fully equal, if not superior to, all others, in the judicious selection, and also in the very delicate and difficult art of hardening and tempering steel dies.

His recent and highly important invention of casting thin iron plates from models, to be mounted on steel beds, and used in lieu of engraved steel dies, has been already described in your pages (p. 36, No. 767): and his studio abounds with simple and ingenious contrivances for facilitating the execution of his multifarious works of art.

During the long protracted (and, by him, undesired) period of his "official leisure," Mr. Pistrucci resumed the profession of a sculptor; he fitted up two workshops in the mint, for private works in marble, entirely at his own expense. In one of these he executed his fine colossal bust of the Duke of Wellington, and in the other, that of Prince Pozzo di Borgo; both of which have been greatly admired.

In illustration of the remarks which I have just made respecting Mr. Pistrucci's ingenuity in devising expedients to facilitate or assist his labours, I send you herewith a description of his improved "Banker," which affords a much readier and more convenient method of changing the position of a heavy mass of

marble, &c., than any hitherto employed for that purpose. There is both novelty and ingenuity in the present apparatus ; and I observe that a patent was obtained by Mr. William Brindley, of Birmingham, in December last, for the application of a precisely similar arrangement of mechanism to the construction of presses of great power. Mr. Pistrucci's banker was made at the well-known manufactory of Messrs. Heaton, Brothers, of Birmingham; and whether Mr. Brindley obtained his idea from that source, I cannot pretend to say, nor is it of any real consequence; for a Mr. Penny exhibited a press, constructed on the same plan, in London, upwards of five years since.

I may hereafter return to the subject of these presses; but, for the present, I shall confine myself to the more legitimate object of this communication.

Mr. Pistrucci's banker (to use commercial phrases) is a very substantial one; it carries great weight, and is not likely to break. It consists of a circular board of oak a, mounted on three legs of ash bb b, composed of two pieces, and strongly bolted together. Iron ties connect the legs to the table, and to each other. A second circular board or platform, c, is supported perpendicularly over the first, by three strong iron screws ddd. The parallelism of the machine is preserved, and the support strengthened, by three steadying-irons ee e, which pass through suitable guides fff: these are furnished with set screws, for fixing the apparatus immoveably at any approved height.*

The platform c, on which the block of marble is placed, is made in three parts: a top and bottom, with an intermediate ring enclosing the gearing, by which the effect is produced. A horizontal toothed wheel is fixed on the top of each of the screws, all three of which work into a wheel placed in the centre; on the axis of this central wheel there is a large bevel wheel, which is driven by a pinion on the winch-handle g; so that, by turning the handle, the three screws are made

In this machine the steadying-irons have been placed opposite each of the screws; but, in Mr. Pistrucci's plan, they are placed more judiciously, intermediately, so as to have six equidistant points of support instead of three.

we

Just as well might an Englishman fatten on the red earth constantly seen on the banks of his favourite Thames (the colouring matter of which is innumerable animalculæ), and boast of his subsistence on inorganic matter! The mushroom and the olive, brought forward by Junius Redivivus"-being both organic substances-by no means assist his argument: he seems to depend greatly upon his assertion that " scarcely know where the stone ends and the vegetable begins, or where the vegetable ends and the animal begins." It has long been a favourite notion with speculative naturalists, that organised beings might be arranged in a continued series, every part of which, like the links of a chain, should be conencted with that which preceded and that which fol lowed it. Linnæus was even impressed with the idea, that nature, in the formation of animals, had never passed abruptly from one kind of structure to another. But the idea of a chain, or continuous gradation of being, was cherished with enthusiastic ardour by Bonnet, who, assuming man as the standard of excellence, attempted to trace a regular series, descending from him to the unorganised materials of the mineral world. Many other writers have adopted this fanciful speculation; but none have carried it to a more extravagant length than Lamarck, who blends it with the wildest and most absurd hypothesis that was ever devised, to account for the diversities of animal structures.

The fact is, the parts, which by their assemblage constitute an organised body, when compared with inorganic matter, exhibit in their chemical, as well as in their mechanical characters, the most well-marked and striking contrast. The solids and fluids of which organic structures are composed, differ very materially in their chemical constitution from the productions of the mineral kingdom. Their elements are combined by a much more complicated arrangement, and united by less powerful affinities; or rather, the balance of affinities, by which they are held together is more easily de

*The peculiar office of fat as a magazine of nutriment, for the support of the body during the period when food is scarce, is strikingly exemplified in numerous instances, especially in all the hybernating animals.

stroyed, and thus proneness to decompo sition is constantly present.

It is an incontrovertible law of nature, that a constant supply of nutritive matter is essential for the continuance of life; and when we come to analyze the proximate principles from which animal nutriment is derived, we find them reducible to the following: namely, fibrin, albumen, oil, gelatin, and sugar; together with a few others, such as osmazone, which are of minor importance. Perhaps the most exact classification is that of Magendie, who refers all alimentary substances, whether animal or vegetable, to the following heads: namely, farinaceous, mucilaginous, saccharine, acidulous, oily, gaseous, gelatinous, albuminous, and fibrinous. These are adapted to the purposes of nutrition by the functions of assimilation, absorption, circulation, and respiration.

When any of these proximate principles are found to exist in inorganic matter, then-and not till then-will man find nutriment therein. “Junius Redivivus" may perhaps go on to ultimate elements; but this will advantage him nothing, as they form organic substances only in definite proportions.

It is too frequently the practice with flighty theorists, though both unphilosophical and unjust, to push their speculations beyond all reasonable limits; and, when challenged, to reply, that " philosophy is not yet a perfect science;" and when met by some insurmountable difficulty, to content themselves by declaring, that "our chemistry is at fault."

I would merely ask, was it not by similar baseless arguments, and such idle speculations of old, that the reign of ignorance was so long perpetuated? and shall we-after the lessons of a Bacon, and the example of a Newton—suffer imagination to run wild, regardless of all recorded experience.

I trust there are none who would assert that our knowledge is perfect, even with reference to the points now under review; but this may be admitted, that whatever further insights the perseverance and ingenuity of man may obtain, into the mysterious operations of nature, we are even now in possession of certain facts, and have acquaintance with several governing laws, that will continue to operate, unchanged, to the end of time. We have positive data to proceed from, however limited our range beyond; and