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THE RAILWAY SYSTEM.

tensions to support, are so ridiculously absurd, as to afford infinite amusement to any one not bitten with the railwaytarantula. There is one, the "South End and Hole-Haven" (magnificent in sound, at any rate), which proposes to throw off branches to "Tilbury Fort, Mucking, and other trading places on the line!" What can sound more feasible than this, and what dreamer of railwayriches would be so foolish as to dispel the illusion by referring to the matter-offact authorities, who tell us that Tilbury Fort is a mere barrack for a company or two of soldiers, and Mucking a village with nothing remarkable about it, and containing nearly 200 inhabitants, with one public-house for its only " trading" establishment? Such is the fuct, and doubtless many more such glaring instances of wholesale misrepresentation might be produced by any one who would devote the time and patience necessary to the examination of the ponderous mass of railway prospectuses which have crowded the columns of the newspapers for the last few months. He who should do so, and publish the results of his labours, would be a great publie benefactor; but it can hardly be expected that the cause of Truth should find a champion stout enough to put to the rout the thousand champions of the cause of something else, who are every day being called into existence by that most powerful of motives, self-interest.

It is not a little singular that the public are offered the choice of three very different species of railway to Blackwall

in the air, on the earth, and under ground. The first is Sir John Rennie's, similar to that of the Greenwich Railway, to be supported on arches; the second, the northern line, to run as nearly as practicable on the surface; and the third, and most eccentric, the pneumatic, which is to be a subterranean tunnel all the wav.

This latter is not projected by the redoubtable Mr. Pinkus, but by Mr. Vallance, the original promulgator of the idea, who was to have finished a railway on that principle to Brighton by this time, if he could have raised the necessary capital. Poor Mr. Pinkus appears to be in the back-ground altogether.

Amidst the railway-rage, which for some time seemed quite to have annihilated common-road locomotives, several schemes have at length appeared for the

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introduction of that method of superseding horse-flesh. The "London and Holyhead Steam-Coach and Road Company" has indeed fairly given up the ghost, notwithstanding the efforts of its parents, Messrs. Macneil, Alexander Gordon, and Co. to keep it alive. In its place, however, have sprung up two new Companies, each of which only requires "the necessary pecuniary supplies" to drive all horses off the road at once. One of these rejoices in having secured the services, as engineer, of a Mr. Fraser, who rests all his claims to success on his discovery of the impracticability of the attempt to unite lightness with power in road steam-carriages; and, accordingly, proposes to smoke along at a dozen miles an hour in vehicles of a ponderosity far exceeding that of the broadest-wheeled waggon that ever crawled along at the rate of 14 miles in 15 hours! We do not find that Mr. Fraser has yet launched one of these wonder-working masses, and until he has, perhaps he had better leave the field to engineers of more experience -Mr. Hancock, for instance, who has taken the road again with great gallantry, and certainly with a greater improvement in point of speed. Were the question of expenses only solved, so that the carefully-guarded secret as to the extent of wear-and-tear might be safely made known, to all appearance Mr. Hancock would have nothing but plain sailing before him, but "there's the rub."

In point of cheapness, steaming by land can hardly ever equal steaming by water. We cannot expect, either on common road or railway, to be conveyed to Hull for two shillings-the present fare by sea (a distance of at least 300 miles); nor, even if the suspension-bridge across the British Channel were fairly erected, could the journey to Boulogne well be effected for less than five shillings, the present rate per steamer. Notwithstanding this, I believe it seldom happens that a railway projector does not calculate upon securing every particle of traffic on his line, to the exclusion of every other mode of transit. The possibility of competition as an element, that never enters into the composition of a railway prospectus; the fortunate shareholders of the concern whose glorious prospects are being held out to view, are always to engross the whole trade, not only of their own line, but of all the

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Sir, The uses of soils with respect to vegetation appear to be threefold; 1st, to afford a firm and erect standing to the plants, by allowing their roots at once to spread through and to obtain a sufficient holding for this purpose; 2nd, to administer moisture to them in such quantities as are requisite to serve as the medium of maintaining their vitality, and of furnishing them with nutriment; and 3rd, to yield certain extracts in a state of solution in the water, which conduce to the sustenance and peculiar properties of plants. From many experiments and facts, well known with respect to the continued fertility of certain soils, consisting of the three principal earths, chalk, clay, and sand, duly admixed and combined, it appears probable that a very small proportion of earthy matters enters into the substance of plants, and consequently that water and carbonic acid are the principal materials which conduce to their nutrition; the carbonic acid and a portion of the water undergoing a decomposition within them, by the action of light in connexion with their organic structure and chemical properties. It is a curious and interesting question how far plants are indebted to the water, the carbonic acid, and other extracts from the soil, for their growth, verdure, &c., and in what degree they owe them to the functions of the leaves and stem upon the air, vapours, and light of the atmosphere. This last appears best adapted for acting electrically upon them through each of those elements, in the several ways we have described; while the soil is evidently essential for the several purposes abovementioned, especially the two former. The earth appears nearly alike useful to plants by administering moisture to their

roots, and by yielding exhalations to the atmosphere. It seems to have been well ascertained that carbonaceous matter in the soil is highly conducive to their growth and luxuriance, and yet it is much more evident that carbon is furnished to the leaves from at least an aqueous atmosphere impregnated with it, than that it is imparted to them from beneath by means of the roots and stem. In proof of this I inserted the stem of a sprig of spearment in water, impregnated with carbonic acid, sufficiently to produce a copious production of oxygen by the action of the leaves; while its upper part was immersed in an atmosphere of water, from which the air had been expelled. Very few globules now issued from the leaves; but on reversing the waters, the leaves being placed in the impregnated water, drew from it copious globules of oxygen. And here it may be observed, that minute but numerous globules of gas settled on their upper surfaces, while large globules were issuing from beneath, the former probably consisting of carbonic acid, which, in passing through them, deposited its carbon and was converted into oxygen.

On

An experiment, however, made early in the month of November, when the leaves are assuming their autumnal hue, and rapidly disappearing, seemed altogether favourable to the conclusion, that the stem draws up carbonic acid with the water, and diffuses it over the leaf. the 2nd inst., leaves of the vine, green, fading, and yellow, had their strigs inserted in water impregnated with the aerial acid; and corresponding ones in unimpregnated water; all the leaves being alike exposed to the action of the air and sun. On the 5th the green leaves of the impregnated water retained their greenness and vigour, while the leaves of the unimpregnated water were nearly seared. On the 13th the former had assumed a reddish hue, and in this state dropped off, while the latter were quite withered, but adhered to the stem. Now M. Macaire, having observed the respective effects of acids and alkalies on what he terms the chromule of the leaf, the one in imparting to it a red or yellow, and the other a green colour, drew the general conclusion that "the resin of the leaves which have undergone an autumnal colouring, seems to be nothing but green resin oxygenated, or having undergone

ELECTRO-VEGETATION.

a sort of acidification." To what is this acidification of the leaf in the autumnal season owing, but to the diminished action of the solar rays, in consequence of which a portion of the carbonic acid remaining undecomposed within them produces this change in their colour; but from the above simple experiment, it appears to be drawn up and diffused over their surface through the stem, together with the water, and thus it seems to occasion also the drop of the leaves, while it is proba bly instrumental in preserving some degree of vitality in the plants, instead of suffering them absolutely to wither and perish during the winter season.

So far

as any inferences can be deduced from these minute, single experiments, it would appear that carbonic acid is conveyed to the leaves, both through the stems from the sap, and from the moisture of the atmosphere, the larger portion coming from the latter source when opportunities are afforded by the presence of moisture thus impregnated in it, or, perhaps, also by dry carbonic acid floating in the air; but such inquiries require to be more extensively pursued before we can arrive at certain and correct conclusions.

As much hydrogen enters into the substance of plants, and, from various experiments, it appears to unite with carbon in producing the green colour of the leaf, it must either be obtained internally from the sap, or from the atmosphere, by an action of the leaves. This is in general probably accompanied with the decomposition of water, to which process it is likely that there is a similar necessity for the agency of light, as in the case of carbonic acid. We are not aware that in the ordinary course of nature hydrogen, in a state of separation from oxygen in the form of water, is ever presented to the leaves. But when they are by artificial means, or by some extraordinary concurrence of circumstances, exposed to such an atmosphere, the effects are remarkable. I have repeatedly observed that sprigs of spearment not only live equally well in it as in common air, but that their verdure is heightened; and for one or two days after being introduced to it, their ordinary transpiration of moisture has been almost wholly suspended! M. Humboldt informs us, that he met with green plants growing in complete darkness at the bottom of one of the mines of Friesburg, in which hydrogen gas

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abounded; and Dr. Priestley gives the following interesting account of several experiments with the willow plant growing in "inflammable air" obtained from a marsh-probably carburetted hydrogen:-"I put the stalk of a willow plant into an inverted jar full of water, while the top of it was in a jar of inflammable air. In these circumstances a small quantity of air was collected in the inverted jar, and it was evidently better than common air." In another experiment three-fourths of an ounce measure of very pure oxygen was collected under the same circumstances. "A sign of the great vigour of the plants growing in inflammable air was the vivid greenness not only of the leaves that were in the air, but of those also that were under water, and the length of time that they continued in those circumstances; whereas, in general, when the plant was in common air, the leaves that were under water soon became discoloured and perished. These leaves, on the contrary, not only continued green, but were always loaded with air-bubbles." In some experiments on water impregnated with carbonic acid, the docter observed an abundant growth of green vegetation, while water unimpregnated with this gas yielded no such result. From these facts and experiments compared together it appears evident that carbon and hydrogen combine in producing the substance and the verdure of the leaves. In the ordinary course of nature the hydrogen is probably obtained by a decomposi tion of water; but in those cases in which it is presented to the plants in a state of separation from oxygen, the union of carbon and hydrogen appears to proceed with extraordinary facility. As the case related by M. Humboldt is perhaps the only instance in which green leaves have been observed growing in darkness, we have reason to conclude that light is the ordinary instrument by which hydrogen, as well as carbon, is separated from its oxygen; but as in that case there appears to have been no instrument, excepting the caloric of the hydrogen to supply its place, are we not necessarily led to the inference that they are, in this respect at least, identical? It seems highly probable that carbonic acid coming in contact with hydrogen gas in this mine, their tendency to union in the substance of the leaves became stronger than their affinity

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NEW MODE OP HEATING BOOKBINDERS' LETTERING-TOOLS.

to caloric in the gaseous state, which thus becoming disengaged, performed the function of light in promoting their union, and also in carrying forward the aqueous transpiration of the plants. Priestley's willow plants appear to have been under similar but more advantageous circumstances from the presence of carburetted-hydrogen; as in this case, light and caloric probably co-operated in forwarding the action of the plants upon the two elements of carbon and hydrogen, and producing the disengagement of the oxygen. What is the general inference to be deduced from the above premises? Is it not that the soil administers the due supplies of moisture in conjunction with such other materials as it holds in solution to the roots of plants, which, by the action of the solar fluid, chiefly under the form of light, are essential to their vitality and growth? And is not this effect, together with the decomposition of both carbonic acid and water by the action of the same fluid on their upper extremities, so much concurring evidence in favour of the electro-chemical agency of the same pure imponderable fluid in carrying forward the several processes of vegetation?

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conclude, that bookbinders' tools might be heated much more speedily, and with better effect, by dipping them into fused lead, or printers' type metal, or an alloy of lead and tin, than by exposing them, in the usual way, to a coke or charcoal fire. Sand floating on the surface of the fluid metal would, in a great degree, pievent the escape of its fumes, and also retard its combination with the oxygen of the atmosphere.

An experienced bookbinder, to whom I stated my views, expressed his belief, that the adoption of the plan would be found very advantageous in finishingshops, where gilding forms so important a part of the business. I remain, Sir,

Derby.

Yours respectfully,

T. COGGAN.

EFFECT OF THE VELOCITY OF AIR UPON ITS USE IN SMELTING IRON.

M. Teploff, one of the Russian Mining Corps, in an article on the improvements recently introduced into the smelting of iron in Russia, makes the following statement. In the smelting furnaces of the Ural, where the quantity and velocity of the blast are properly regulated, 14 of pig iron is obtained by 1 of charcoal fuel, while in other furnaces they obtain but 4 and 6 by the same comsumption of fuel.

The velocity of the blast being increased, the heat within is increased, without a corre sponding consumption of fuel. In an experiment made by order of the government, it was found that one hundred cubic feet of air, under a pressure of two inches of mer cury, produced the same effect as two hundred cubic feet, under a pressure of one inch, with this difference, that, in the latter case, twice the fuel was consumed, which was required in the former case.

In one furnace which is mentioned, 22,000lbs. of iron were obtained in twentyfour hours, by 16,000lbs. of charcoal. Previous to the due regulation of the draught, they consumed twice this amount of fuel for the same yield of iron.

This economy is obtained by duly proportioning to each other the size of the blast pipe, and the pressure of the draught. The relation of these to each other, varies with the furnace.

M. Teploff asserts that the results thus obtained exceed those with the hot-air blast, but it does not appear that any comparisons have been made under his examination, and with the charcoal fuel.

To regulate the draught, it is recom

EDWARD TROUGHTON, ESQ.

mended to place two mercury or water-gauges, one near the blast-pipe, the other near the governor of the blowing-machine. By varying the pressure, and the diameter of the nozzle of the blast-pipe, making the latter smaller as the former is increased, and vice versa, the best proportion is to be ascer tained. Annales des Mines, vol. vii.

EDWARD TROUGHTON, ESQ., F.R.S., L. AND E., F.R.A.S. AND F.R.S.C.E.

The late Edward Troughton was born in a small village in Cumberland, in the year 1754, where he received merely a common education in the village-school. When seventeen years of age he came to London, and apprenticed himself to his brother John, a respectable mathematical instrument-maker, carrying on business at No. 136, Fleet-street; and when cut of his time was taken into partnership, and ultimately succeeded to the business, and ever after continued to reside there; and it is not a little remarkable, that the same spot has been successively occupied by mathematical instrument-makers of celebrity for nearly 200 years; and here a Sutton, a Wright, a Cole, and a Troughton, laboured with unwearied zeal for the advancement of science. In a very short time after Mr. Troughton's arrival in the metropolis, he began to display that great originality of genius, which in the end made all scientific men look up to him for the means of prosecuting their pursuits with the fullest effectfor be it remembered, that the sublime study of astronomy must ever be obscure without instruments of the most accurate execution, because the theorems of mathematicians are useless without data to act on-and with this he supplied them; presenting to all competent persons the means of dividing instruments with the most perfect accuracy, and by which they have been graduated to such a degree of exactness, that error is not to be discovered in them even by high optical powers; and many of his instruments of large dimensions are placed in various observatories, and by them a catalogue of the fixed stars, and the sun, moon, and planets, are now ascertained, and published in the Nautical Almanac. Many other skilful artists have also acted upon his improvement. The stability, accuracy, and commodious arrangement of his instruments leave nothing for the astronomer but to use them with care, as it is a fact, that the declination of some of the fixed stars have been ascertained by them to one-third of a second. It is unnecessary to follow Mr. Troughton step by step, but a reference to a few of his great undertakings cannot be without interest. The Royal Observatory is furnished with a mural circle, a transit instrument, and a zenith

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sector, all of his contrivance; and the last was completed by him when in his 79th year: also, an equatorial instrument, for Trinity College, Dublin; and which is now stationed at Armagh and a meridian circle (made for Stephen Groombridge, Esq.), now belonging to Sir James South; the whole of which are specimens not perhaps to be equalled either in beauty or figure, or perfect accuracy. He also remodelled the continental instruments so as to make the repeating circle of the Chevalier Borda, and the reflecting circle of Mayer, almost original inventions of his own., His nautical instruments, also, both as to construction and accuracy, are beyond all praise; and by them the mariner is now indeed enabled to mark a road on the trackless ocean." Nor were his great labours wholly unrewarded; for the Royal Society, in 1809, presented him with the Copley Medal, for his elegant and valuable paper on Dividing. On the 7th of April, 1823, he received the freedom of the Clock Makers' Company; and in January, 1830, the King of Denmark presented him with a valuable gold medal, as an acknowledgment of his great and important improvements. In his latter years he devoted himself entirely to severe study and scientific pursuit; and laboured not merely in abstract theory, but for the improvement and direct benefit of the civilised world. Retaining his faculties to the last, he died on the 12th of June, 1835; and, according to his request, his remains were deposited in the General Cemetery, Kensall Green; and were followed by many, and deeply regretted by all the scientific world.-New Monthly Magazine.

NOTES AND NOTICES.

New Power.-We learn from Frankfort that there has been communicated to the Society of Natural Sciences of that city a discovery of a new motive power, created by means of a galvanic battery, the action of which will supersede the uso of steam, be more powerful, much less expensive, and less dangerous.-Morning Herald.

National School of Design.- In the course of a discussion which arose in the House of Commons on Monday last upon the vote of 25 8607, for new buildings at the British Museum, the Chancellor of the Exchequer (Mr. Spring Rice) said, that he in-. tended to lay before the House a supplementary estimate for the purpose of establishing a school of design, with a view generally to the cultivation of the popular taste, and to the practical improvement of our manufactures. He trusted that the proposed institution would be well suited to serve as a inodel according to which other schools might be formed in provincial places.

The Thames Tunnel.-This stupendous undertaking is proceeding s owly, but steadily towards completion; nor has any obstruction occurred since the works were re-opened. The men work night and day; there are three sets of men employed, which relieve each other every eight hours. Each set consists of 112 men, and there are numerous supernumeraries, ready to supply any casual va cancy. During the eight hours of work they are

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