using fir or other soft woods in the construction of steam-vessels, nothing but oak or other hard wood should be used. The common plea for the use of fir, is its lightness; but in order to obtain the requisite strength, it is used of greater substance, and therefore the total weight of the materials is increased so as to be nearly the same as if oak only were used. I very much incline to the belief, that when thoroughly saturated with water, the fir planking is equally as heavy as oak. Another plea for the extensive use of fir for planking is, the great lengths which can be obtained. This is an advantage, undoubtedly; but it is frequently completely thrown away by the exceedingly unskilful combination of the parts. There are now in existence some of the earlier steam-boats, built entirely with oak; these vessels do not present any signs of weakness or giving way, whilst many others which have fir planking, although less than one-third their age, are yielding in several parts, and some of them either actually extensively repaired, or requiring to be so. There can be no question but that it is contrary to sound policy to use so large a quantity of fir in the construction of steam-boats, even if cost only be taken into consideration. The difference per cent. in the prime cost between oak and fir plank, applies only to the material— the workmanship and fastening is the same in both cases; but, as experience has shewn, the durability of the one is two or three times longer than the other. If we assume the difference in cost of material to be 50 per cent., the cost of labour and fastenings will be equal to the cost of the oak, or 50 per cent. on the price of the fir; the duration of the oak will be from 2 to 3 times longer than the fir. The account will stand thus:For Fir Planking. Material. Labour and fastening.. 150 For Oak Planking. 100 250 150 Material 300 Assuming that fir will last half the time of oak, its cost for the same period will be 500; whilst oak would cost but 300, to say nothing of the loss that must ac crue from loss of freight during the repairs. That the practice of planking steam-boats with fir should have prevailed so extensively, can only be accounted for upon the principle that present_advantage and saving is alone regarded. I should be glad to see an end put to the practice of using fir for planking seagoing steamers: it is unfit for the purpose, both as it respects strength and durability; a great number of instances might be quoted in proof of this statement: instead of the present cheap method of running these vessels up, a more careful and scientific method of construction should be adopted. It was my intention to have suggested some improvements upon the present method of construction; but, as I have for the present occupied too much of your space, I forbear. I am, Sir, yours &c. GEORGE BAYLEY. THE IRON STEAM-BOAT 66 RAINBOW" -SPEED OF THAMES STEAMERS. Sir,-The good folks of Liverpool appear to be in a fair way to bear the palm of boasting from their hitherto successful rivals, the Americans; indeed I think upon the subject of the above-named vessel, they have beaten them hollow. Fame has blown herself hoarse during the last fifteen months, trumpeting the praises of this wonderful vessel; when the keel was laid long since, various were the statements made by the friends of the builder and engineer, as to what her intended performance was to be; fifteen miles per hour was said to be the speed contracted for, and for every mile above this small speed, some thousands per mile were to be paid. She was to be constructed of iron, instead of wood, of the great length of 190 feet, and 180 horse-power, with 5 feet draught of water only; certain it is, that the proprietors of the little slow boats on the Thames trembled when it was known that this nonpareil was on her way to London-the river captains were chapfallen-the owners of the steamers thought of burning them—oak was at a discount, and iron at a premium. The Rainbow has at length appeared, and run the race on the Thames, firstly with the old Emerald, a third-rate boat, of 140 horse-power, running from France to London, heavily laden, and the deck lumbered with cargo; which vessel she passed, to the infinite delight of her owners. And shortly afterwards, to crown her triumphs, ran with the little Vesper of 70 horse-power only, and in a race of one hour and twelve minutes, gained, as they state, four minutes upon this vessel, of scarcely more than onethird her own power, and having passengers on board at the time; in fact, there is little doubt but the Vesper would have been quite a match for the Rainbow, had they both been in the same trim. The people of London would have considered this performance a great failure, had the immense advantages this iron boat possesss in length and power (180 horses,) over her little opponent (70 horses) been considered; and which ought to have given her, at least, one and a half miles per hour more speed; but the Liverpool friends of the Rainbow think otherwise, and seem so exceedingly delighted, that newspapers detailing this glorious achievement, are being sent about the country cost free. The truth is, her trials have only begun; there are yet three or four boats for her to run with, all faster than the Vesper, and of infinitely less power than the Rainbow. Why was she not tried with the Ruby, a vessel of 100 horsepower only? This boat can, and has beaten the Vesper from Gravesend to London, from seven to eight minutes; there are also the Star, the City of Canterbury, and the Red Rover; all of these boats are really very fast, and the whole of them, the Vesper included, will, I am confident, beat the Rainbow if loaded equally; that is, one passenger and luggage for every horse-power the contending vessels possess: thus the Rainbow should carry 180 passengers, when the Vesper carries seventy, and so on. Should the owners of the Rainbow be inclined to run her with the Ruby, I understand the captain of that vessel has 1007. at his command, to run her against any vessel in Europe, the Rainbow, of course, included. By the following statement of speed, your readers will be better enabled to form an opinion of the performance of the Gravesend steamers, and thus, by comparison, what the speed of the Rainbow really is; (I now speak of speed through still water by the power of steam alone, as measured by a statute mile marked off on the bank of the Thames in Long Reach, where all the London vessels, as well as the Admiralty ones, have their powers tested). The Ruby, well known as the fastest steamer afloat, goes exactly 13 miles per hour, as has been ascertained by repeated trials. The Star and Vesper 134, the City of Canterbury and Red Rover 13; all the other Gravesend steamers above twelve; and I have no hesitation in saying, that the Gravesend steam boats, taking them all, are, without exception, the fastest vessels in Europe; and I fully believe, that when vessels have been successively brought from the ports of Glasgow, Liverpool, and other places, to compete with London built and fitted steamers, the different parties could not have deceived themselves and others, as they have done, had they known the real speed of these celebrated vessels. I will now give you the performance of some of these boats, after the Yankee fashion, that is, reckoning tide and every thing in favour. On three different occasions last season, the Ruby made the passage from London Bridge to Gravesend with passengers, including stoppages, in one hour and thirty-five minutes; which, allowing five minutes for stoppages and interruptions, would make the time of running 13 hours; the distance is computed to be thirty miles; here then, Mr. Editor, is twenty miles per hour! This, I think, is the greatest steam-boat performance upon record in this country. The Star has also done it under one hour and forty minutes; the Vesper, the Diamond, the Gem, and most of the other Gravesend steamers do it often in one hour and forty-five minutes, including their loading of passengers and the stoppages; this gives seventeen miles per hour. What is here stated can be substantiated by numbers of gentlemen who are daily in the habit of travelling by these splendid vessels; but the Londoners have never thought of boasting to the world as the Americans are in the habit of doing, that their vessels always go at the rates just stated, well knowing, that going through the water, and overland, as it is technically termed, are two totally different things. In conclusion, Mr. Editor, I feel quite confident, that there are plenty of builders and engineers in London, who are quite competent to build and equip a vessel of timber of the power and length of the Rainbow, that will beat her a mile an hour. I am, Sir, your obedient servant, PISTON. Limehouse, May 31, 1838. STEAM NAVIGATION TO INDIA--SPEED OF THAMES STEAMERS. Sir,-It is difficult to bear the ridicule of others, without either feeling one's temper ruffled, or suspecting that there really is something in our conduct or opinions not consistent with propriety. Now it does so happen, that upon seeing the communication of your correspondent "H." in No. 772, page 120, my temper was unruffled at the sneer with which he commences his letter; and I can assure him, that until within a few days, it has never been my good fortune to meet with a copy of Messrs. Seaward's pamphlet, although I happen to have been a constant reader, and an occasional correspondent of the Mechanics' Magazine from its commencement. The assurances of your correspondent, "H.," that "a perusal of the more recent num:bers of the same work" will relieve my mind from the apprehension "so vividly" expressed for the safety of our maritime pre-eminence in the East, would be, doubtless, very consolatory, if they met the case; but, as you well know, the pressure from without" was required to produce even a show of attention on the part of the government to this important object; and then much valuable time and talent was wasted in the attempt to render the navigation of the Tigris available to commercial purposes. From the tenor of "H."s remarks, he appears to be very desirous of inducing the belief that steam navigation is very general in India. If so, it is passing strange that, in common with many others who have access to the sources of early and accurate information upon maritime affairs, he should have overlooked the fact, that steam navigation in India was common long ago, and that we should have been impressed with the belief that steam navigation was still in its infancy in that part of the British empire,-so much so, that even the comparatively recent colony of New South Wales had made greater progress, and has actually been in possession of a more extended and frequent communication by steam-vessels, than our Indian empire. Captain Grindlay, in his excellent remarks on steam communication with India, has most clearly shewn, that its introduction has been covertly opposed or retarded, by some influence or other, which has been too powerful for the exertions of private speculators to overcome at present. It is certainly true, that the force of public opinion is compelling the reluctant compliance with a part of the demands of a just and enlarged view of the necessity of commercial enterprise, by providing for the more frequent communication with the mother country via the Red Sea; but as floating straws indicate the direction of the current, it would seem that this communication was intended to be maintained by vessels unsuited to the purpose. The Hugh Lindsay has long ago received her character as an inefficient vessel, altogether unsuited to the purpose. The Enterprize is somewhere in India; her qualifications are tolerably well known. The Atalanta and Berenice, sent out last year, are certainly efficient vessels, as it regards power and capacity; but it is with me a matter of great doubt whether the extensive use of fir planking was prudent for a vessel designed to navigate the Indian Seas. My reasons for doubting its propriety are deduced from the facts which frequently come under my observation. The Semiramis, late the City of Waterford, was the last sent out to reinforce the steam flotilla; of her excellencies it is unnecessary to speak; she is principally planked with fir, and was built for carrying a large cargo. There are three other vessels contracted for in this country, to be built expressly for the service. I have seen the model, and from my knowledge of the constructor, I have every reason to believe that they will be really efficient and suitable ships for the purpose. Thus, Sir, this large East Indian steam flotilla at present appears to consist of two efficient steam-vessels ;-one whose qualifications are not quite all that can be wished, and two (?) others altogether unsuited to the purpose. Whether these will be sufficient to maintain a sufficiently frequent communication with England via the Red Sea, and with our most distant dependencies in the East Indies, I leave to the candid judgment of your readers. The Dutch are building some steam-vessels to navigate the Indian Archipelago; and, according to present appearances, will be in possession of that field before our active Indian Government, with its "flotilla of steam-vessels," already in the East. I trust that the merchants in Calcutta will rouse themselves, and, by arrangements with their fellow-subjects in New South Wales, forthwith take measures for the establishment of a steam communication through the Indian Archipelago, and thus carry into effect the excellent suggestions of Capt. Grindlay and others, who have "long ago" suggested its propriety and necessity; and then I, for one, shall not fear the permanent maintenance of our maritime pre-eminence in those seas. With regard to the difference between myself and the Messrs. Seaward, as to "the speed which might be kept up on the voyage to India,” my calculation was made on the speed which has actually been maintained by the Atalanta and the Berenice: Messrs. Seaward, in their calculations, assumed that vessels of a much larger class should be employed. If this were the case, I have but little doubt but that they would be found to be correct. The case referred to by me, was one in which the usual nautical miles were used; but the report was at variance with the facts, as was shewn by the gentleman at the time of the trial; and the vessel in question did not go more than from 11 to 11 miles an hour, instead of 14, as the other parties asserted. Subsequent trials have confirmed the correctness of my friend's report. Í have no hesitation in repeating my conviction, that a speed of 14 miles an hour has not yet been attained by steam alone, notwithstanding the statements of "H.," who, by the way, seems to have fallen into the common error, as to the actual distance between Blackwall and Gravesend, which, I believe, does not exceed 18 statute miles; and I have it on unques tionable authority, that the greatest speed ever attained by means of steam alone, under the most favorable circumstances, did but just exceed 13 miles per hour. It is far from my wish to discourage the praiseworthy efforts to increase the velocity of our steam-vessels, but, on the contrary, have every inducement, both official and private, to promote the improvement of naval architecture in all its branches, to the utmost of my ability. It seems that "H." disapproves of the patent condensers of Mr. Hall, on board the Sirius, and would fain have your readers suppose that they were the cause of the difference between her speed and that of the Great Western, altogether overlooking the difference in size and construction of the two vessels. The smaller size of the Sirius would have prevented her attaining the same velocity as the Great Western, even if the two vessels had been constructed upon the same model; but when it is known that the Sirius was built for the British coasting trade, the wonder is, that she should have proved herself so formidable a competitor to the Great Western. It is very probable, that the British Queen will be a much faster vessel than the Great Western, notwithstanding the excellence of her machinery, which is certainly of the most perfect description, and does the greatest credit to Messrs. Maudsley and Co., by whom it was constructed. I beg to apologize for having trespassed so much on your valuable columns, and subscribe myself, with the greatest respect, Your obedient servant, London, June 2, 1838. DR. LARDNER AND THE ATLANTIC Since the return of the Sirius and Great Western, Dr. Lardner has evinced a very pardonable anxiety to explain away and gloss over his too-celebrated declaration against the practicability of traversing the Atlantic by steam. He now wishes it to be understood, that his opinion was, not that the scheme was impracticable, but that it would not be found to answer in a pecuniary point of view. This opinion will soon be put to the test, especially if the idea be realized, of immediately starting a regular series of steam liners from Liverpool, whose enterprising inhabitants, probably, owe their present position, so far in the rear of their ancient rivals, the Bristolians, in some degree to the circumstance of Dr. Lardner having made their town the scene of his wet-blanket prognostications. The Great Western has set out on its present voyage with more "malice prepense" than ever against the worthy Doctor, having taken from England a sufficient quantity of coals, not only to reach America the grand difficulty, in his estimation,— but to steam all the way back again, without troubling the good folks of New York for a supply! This may almost be complained of as an offensive personality. Another point on which the Doctor relies, on behalf of sailing-vessels, is the fact, that the regular liners which left England nearly at at the same time as the Great Western, arrived there nearly as soon,-to wit, in twenty-six days, the Great Western having taken fifteen and the Doctor quotes this speed of the sailers in proof that the passage, after all, must have been a favourable one. If the same proportion between steaming and sailing continue, as it most probably will, it requires no conjuror to predict that steam will soon be "monarch of all she surveys," in the Atlantic, notwithstanding the indifference with which Dr. L. regards the trifling disparity. The proportion has been most admirably kept up on the return voyage,—the Roscoe liner having arrived at Liverpool nearly a fortnight after the arrival of the Great Western at Bristol, with "fresh news" from America, one day later than that brought by the steamer! The Liverpoolites may well be anxious to redeem their reputation by entering the field, even late as it is, as soon as possible. It is understood that the Columbus, a vessel on a less gigantic scale than the Bristol leviathan, and fitted with engines on Mr. Howard's principle, is now nearly ready for her first trip from their port. Meanwhile, the owners of the Great Western have already a second vessel on the stocks, of even larger dimensions than their first; and the British Queen is expected to astonish the Yankees, some time before Michaelmas, with a specimen of London shipbuilding. It may be regarded as an unerring indication of Dr. Lardner's wish, "under existing circumstances," not to draw too much public attention to his opinions on the subject, that his intended article in the June number of the Monthly Chronicle, on “ Ocean steam ers," has been withdrawn, at the eleventh hour, although it formed a prominent attraction in the advertised list of contents, previous to the arrival of the Sirius and Great Western. Alas! alas! what havoc does experience make of the speculations of the learned! BILL TO REGULATE THE SPEED OF THAMES STEAMERS-WATERMEN'S WHERRIES TURKISH CAIQUES, &C. Sir, I see by the papers, that a bill is being smuggled through the "honourable house,' to limit the speed of steamvessels navigating the river "below bridge" to five miles an hour. Now if this limitation of pace were declared to be enacted in order to prevent collisions, there would be some sort of sense in it; but the avowed reason is, the protection of the watermen's wherries from the swell of water, otherwise waves, caused by the steamers' speed. This piece of legislation is beautifully on a par with many others of the dull day-dreams of our night-walking legislators! Because the London watermen choose to build their boats on such a plan as to render them the most unsafe that any inventive genius could devise, the great national advantage of steam-navigation is to be cramped, and squeezed, and cut down, to suit the sea-worthiness of a London wherry! About a year ago, I addressed the Morning Chronicle and the Times newspapers on this subject, but my voice being neither gold nor silver-toned, remained unheeded. Sir, I think that you will take a proper view of this mechanical question; and if you only bestow upon it half the pains, the logic, and acumen which distinguish your excellent remarks upon the copyright bill of Mr. Talfourd, and which once did the like by the new patent law, you will confer a benefit upon those (the steam-navigators) who confer a vast benefit on society. I am not cavilling at a regulation without being able to supply a reason and a remedy. The whole question lies in the improper construction of the wherries, at least as far as the proposers, or rather smugglers, of the bill moot this question. If, I repeat, they had predicated the objection to any more than a certain rate of speed to steamers, upon the plea of other vessels being unable to avoid collision, it would have been another affair; |