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ISUUSISH Sir, I have noticed in several Nuinbers of your Magazine such wonderful stories of steam-engine work, that at first I set them down as of American origin, but from a passage in No. 661, I see that they are from no further off than Cornwall, which is called "the nursery of steam-engines," and that "all the world knows it!" If the article a had been applied to nursery in place of the, it would have been perhaps more just to some of your readers, tor people in other parts of the kingdom besides Cornwall have been sendeavouring to improve the steam-engine. A či 15

CORNISH STEAM-ENGINE WORK.

It is truly said, "that the vast quantity of water to be raised from the valuable mines in Cornwall, prompted and rewarded the exertions of Savary, Newcomen, and Watt, so also Trevethick, Woolf, and others, followed; and it appears that the latter nearly as much exceeded Watt, as Watt did Newcomen. It is generally admitted, that the best of Watt's engines could raise at the rate of thirty-two mislions of pounds one foot high, with one bushel of coal this, I presume, e is equal to one million thirty-two feet high (which some think is a more useful shape in which to state the rate); and it is said, that Mr. Woolf was the first to raise so much as fifty millions. If Trevethick had used his high-pressure steatn expansively, according to Hornblower, and condensed it according to Watt, there would not have been much left for others to do; but this combination was left to be achieved by Mr. Woolf, whose exertions I hope will be amply rewarded.

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sha Now, Mr. Editor, as far as fifty millions, and a little farther, I am inclined to believe from my own experience, but I must protest against such a statement, as that eighty, one hundred, and one hundred and twenty-five millions of pounds have been raised one foot high with the consumption of one bushel of coal, until it is described more particularly how such a conclusion was arrived at in place of the common answer by calculation.

It is no wonder these statements have been doubted, and I (as one of a few) am prompted to thus express my doubts, because it is stated that the increase is owing to the improved pit-work, and the system of clothing or casing the cylin ders. I am glad the Cornish engineers have given the cause of the great in

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an

crease, and that it has been accomplished by such simple means. With regard to the pit-work, I am informed by several parties who well know what is going on in Cornwall, that very little improvement has been made in that respect for forty years past, and certainly none for these last twenty-five years. It is well known how difficult it is to make a pump (he it ever so mathematically constructed,) to deliver a quantity of water at a great height to agree with the calculation or the measurement of that part of the pump supposed to be filled and emptied every stroke. Any admixture of air, or ab struction in the suction, or ascensión, or any other imperfection, will produce variation from the calculation; and the deception will be nearly the same, whether buckets or plungers are used. Perhaps some imperfection in the pump-work has led some of the reporters to make a alteration in their figures, for I have known engines to work very regularly as to their number of strokes per minute, when it was afterwards found that the pumps had not delivered their her proper quantity of water. good I tasq As it may be said I have been finding fault without pointing out any remedy, or mode of doing away with the bhjedtions, allow me to say, such statements as I have referred to (which amount to doing four times the work with the same I quantity of fuel as the best of Watt's engines), will never be generally believed until a well-authenticated performance is published of a certain quantity of water having been actually lifted and delivered at least one hundred feet, yards; or fathoms, above its natural level with the consumption of a certain quantity of fuel. This can easily be given in gallons or cubic feet; the account to be kept for one month, as is usual in Cornwall. There can be no want of opportunities in that district to do this. I therefore hope that, in a national point of view, it will be done, especially if Cornwall wishes to keep foremost in steam-engine work. As to the system of clothing or casing the steam-vessels, &c., from which t they say so much benefit has been derived, I had thought that the people in the north-east were pretty well up to jacketing; however, we will all be glad to be set right on this point! if, therefore, the Cornish engineers will prove that four, bashels of wheat they can grind o good flour,

TO THE LATE ECLIPSE OF THE SUN.

Sir,-The late eclipse of the sun, which occurred on Sunday the 15th of May, was one of the most beautiful celestial phenomena which has been observed for many years past. In the north of England, and of Ireland, and in the South of Scotland, it was central and annular; that is, the disk of the moon passed "over the diameter of the disk of

the sun in a line which coincided with the line of observation, or of sight, from those parts parts. The average time of the Commencement of the eclipse in those places, was about 11h. 7m. morning; the annular phase commenced at 48m. past 12, noon, the middle or centre when the disk of the moon centred with that of the sun, and left a ring of light in -breadth of about one-sixteenth of the sun's diameter, occurred at 2h. 21m.; the annular phase ended at 3h. 45m., and the eclipse itself ended at 4h. 56m. The noon, therefore, in those parts appeared Inearly stationary in respect of the sun's disk, for upwards of one to three hours, and afforded a most gratifying period of Lobservation upon this interesting annular -exhibition.

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At Edinburgh the eclipse commenced at 1h. 33m., its middle 2h. 59m., and its end 4h. 19m. The annular appearance there lasted only about 15m. At Greenwich the eclipse began at lb. 51m., its middle was at 3h. 19m., and its end at 4h. 39m. About London the day was extremely favourable for observations; the sky was unclouded, and the air clear; owing to these circumstances, the dark. ness at the middle of the eclipse was not so great as had been generally anticipated. The magnitude of the eclipse in these parts, the sun's diameter, or apparent disk, being taken at 1, was at the middle

0.863 upon the northern limb, that is, nearly equal to nine-tenths of the sun's disk; but the eclipse not being annular in these parts, the light of the uneclipsed portion of the sun was stronger than it was in those places in which the eclipse had an annular appearance. Near London, the centre of the moon passed the line of observation above the centre of the sun about 12 of its diameter, at an angle of elevation with the horizon of about 35o.

The following diagrams exhibit three appearances of the eclipse at the times indicated to each, from observations made about four miles south of London.

It may be observed, that the eclipse increased from its commencement more

4h. 15m.

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rapidly than it went off; so that the disks did not present the same relative appea:>

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Sir,-In the Library of Useful Knowledge, article Astronomy, part 3, pp. 68 and 69, regarding the siderial period of the moon's apogee, it is stated to be 3,232d. 13h. 56m. 168 sec.; and for the siderial period of the moon's nodes, 6,793d. 10h. 6m. 29.952 sec. Now I would feel greatly obliged were you, or any of your astronomical correspondents, to be informed why the siderial period of the apogee is longer than its tropical period, and why the tropical period of the nodes is longer than the siderial period; for, in some works, I find 3,231d. 11h. 57m. to be the tropical period of the apogee, and about 6,798d. 6h. 20m. the tropical period of the nodes? If the periods given by the Library of Useful Knowledge be correct, how are their tropical periods found ?

By giving an early place to this, you will oblige your old and constant reader, ROBERT SIMPSON.

THE RAILWAY SYSTEM.

Sir,-Just in the midst of the prevail ing railway excitement," "it sounded very strangely to English ears that the French Minister of Finance should have adduced, as a reason for continuing the present prohibitory duties on foreign coals and iron, the "fact" (as he called it), that most of the already-existing railroads in England had turned out complete failures, in a pecuniary point of view. It must certainly be allowed, that this assertion was a little too broad; but the Frenchman's view of the matter can hardly be more absurd in one direction, than the ideas of thousands at home must be in the other. Nothing further seems to be necessary now-a-days to procure subscribers to a railway scheme, than to form the project of establishing a line from one town to another, "not already in possession of this improved method of communication"-no matter what may be the extent, population, trade, or manufacturing and commercial importance, of either. It is taken for granted, that as soon as the railway is completed, the traffic necessary to pay an enormous per centage on the capital will follow as a

matter of course. Yet what says the little experience we have yet had on the subject? For what reason is it that the Hogs'-Norton and Dreary Common Rail way has only to issue its prospectus to secure a snug premium for its shares in the market? Simply this, that a railways between Liverpool and Manchester, two towns of immense population, at a distance of little more than 30 miles, ond the commercial, and the other the manu- › facturing capital of the great "northern line" of England-has succeeded to such an extent, that (aided by the attraction of its novelty, which draws passengers to it not only from all parts of Great Britain, but of the Continent,) it pays the shareholders between 9 and 10 per cent. on their capital.*

And this amazing result has been sufficient to transform us all into a nation of speculators! Encouraged by this daz. zlingly brilliant success, having this proof positive before us that a line of railway in perhaps the most advantageous situation that could possibly be selected, will actually yield a something over and above its expenses, we are ready at the first blush to yield assent to the very reasonable proposition, that every peddling market-town ought forthwith to be accommodated with a road, costing the trifling sum of 30,000l. a mile! If the Liverpool and Manchester has paid 100 per cent. instead of 10, the rage for rail ways could hardly have been greater than it is at present. "Can these things be, and overcome us like a summer cloud, without our special wonder ?"

Some of the lines projected, and the grounds on which they rest their pre

We do not think this is by any means a fair view of the case. The Liverpool and Manchester Railway is by no means the only one which has furnished an example of great success to stimulate and justify the prevailing fondness for railway speculations. The Stockton and Darlington has paid still better than the Liverpool and Manchester, and is the older line of the two, (can it be that our intelligent correspondent has never heard of it?) the Edinburgh and Dalkeith, and the Dublin and Kingstown, are also yielding handsome returns to their respective proprietors. It deserves further to be observed, that the dividends of the Liverpool and Manchester Railway Company are limited by their Act of Parliament to 10 per cent. (a limita tion introduced through the influence, and for the protection, of certain canal-owners); and that but for this circumstance, they might be a great deal higher than they are. The limitation of the dividends has the natural effect of keeping up the rates of conveyance, and these again of restricting the amount of traffic.-ED. M. M.

This is the maximum rate. In many cases the expense does not amount to 10,000/. a mile in some it is as low as 6,000 and 7,000.-ED. M. M.

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 fact, 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 públic 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 way. 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 neces sary 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

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