be converted into a longitudinal one of the cutter by a flexible steel band, adapted to different sized cylinders on the axis of the wheel. The first cost of such an engine would be great, but not greater in proportion to the value of the article made, than is frequently found in other manufacturing machines.

J. W. WOOLlgar.

Lewes, January 4, 1844.

CLAIM TO THE DISCOVERY OF A MEANS OF DIRECTING BALLOONS.

Sir,-As the subject of aerostation is at last exciting considerable interest, and as the public appear now prepared to believe in the possibility of its accomplishment, I feel anxious, through your va luable journal, to record my claim to the priority of the invention of giving to balloons a specific direction, and that by the aid of steam, before I shall be eclipsed by a host of imitators. When I say imitators, I do not mean you to understand that any of the plans which have been mooted resemble mine, for, with the exception of Mr. Mason's, every one hitherto proposed has been about as applicable to the purpose as it would be to attempt to guide a vessel in the middle of the Atlantic, by turning the vane at the mast head. I doubt much whether even Mr. Mason's will effect the object in view. You never can navigate the atmosphere without some buoyant power in the first place to float you there, a point d'appui, as it were. If Bell or Fulton, or any of the illustrious men of genius, who first applied the power of steam to vessels had argued thus,

we shall not have a ship which floats on the water whether in motion or not,→→ we shall have merely a raft, which will cut through the water at a much quicker rate, as long as the propelling power is kept up, but no longer," where would steam navigation have been now? Should we have been crossing the Atlantic in twelve days? Would our government now be fitting up steamers for maritime warfare? Would every sea and river in our quarter of the globe have been at this moment traversed by steam-boats of every size and capacity? I trow not! Here, then, is the balloon, which is to the air, what the ship was to the water.

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Give that a specific direction, and you have aerial navigation of the most splendid kind!

It is upwards of ten years since I fully accomplished this, as can be proved by incontrovertible evidence, letters addressed to several of the principal aeronauts in Europe, with the view of bringing it out under their auspices. It is two years since I offered to the British government to convey the mails and passengers across the Isthmus of Suez, which I will engage to do at the rate of fifty miles per hour with the wind, and ten miles an hour against it, in moderate weather, and as the distance in a direct line is only seventy-five miles, it could be accomplished in two hours and eight hours accordingly, at infinitely less expense and personal risk. I am at this moment negotiating to convey an expedition to explore the North Pole, and to ascertain the existence of a north-west passage, and I am convinced that this is a much more rational method, than dog sledges and boats drawn by men advanc ing three miles an hour. If ever it is reached at all, it will be by means of a balloon as first suggested by me.

From

these considerations, I have determined shortly to issue a prospectus for raising * Joint Stock Company, with a capital of 100,000l. in 20. shares, of which due notice will be given, and as a large premium is offered by government for reaching the North Pole-as the capital may be doubled every year, by merely carrying passengers from London to Edinburgh, and from London to Paris what a profitable investment would it be if they should add the mails, which would follow as a matter of course.

I am, Sir, your obedient servant,
JOHN HENDERSON.
Edinburgh, 76, Clerk-street, January 6, 1844.

THAMES STEAMERS THE PRINCE OF

WALES" AND 46 ISLE OF THANET." Sir,In matters of fact the statement of an eye-witness naturally carries a greater weight than any other sort of evidence, and when your correspondent Mr. Henry Osmond, who “is in no way connected with either of the vessels," contradicts the statement as to a trial of speed having taken place between the

Prince of Wales and the Isle of Thanet, on the 25th of August last, on which day he was himself a passenger, it really requires no ordinary amount of scepticism to disbelieve the averment.

It would seem, however, that he is fully aware of the universally acknowledged difficulty of proving a negative, since, after having flatly contradicted the statement, he proceeds to show how in his opinion no such trial could have taken place.

Now as Mr. Osmond professes to "feel a great interest in the subject," and is apparently very anxious to arrive at the truth, he will no doubt be gratified to learn not only that a trial did take place, and that on the very day in question, but that, having been on board the Prince on that occasion, I employed myself in "takin' notes," though at the time I had little idea that I should "prent" them. As these notes were not taken for any party purpose, but simply for my own information as to the actual speed of our first-rate steamers, you may rely on their correctness.

From these notes it appears that the Prince of Wales left Blackwall on the 25th August, at 20 minutes past 12 to resume her station at Margate, and after having made several trials of her speed at Long Reach, (an excellent practice, by the way, and one which if more generally followed would prevent many absurd opinions from passing current,) had resumed her route towards her destination; but as on her way thither the Isle of Thanet was descried ahead, coming up the river, it was resolved to take this opportunity of testing the comparative speed of the two vessels.

The Prince of Wales was, therefore, turned round, and awaited the arrival of the Thanet. At 2 h. 39 m., the two vessels were exactly abeam, and it was soon evident that the Prince had decidedly the advantage in point of speed, having gained upon her opponent from the very commencement of the race. At 2 h. 59 m. we rounded a collier brig, moored nearly in the middle of the river, just above Purfleet, and took a fresh course for the next reach of the river. At 3 h. 24 m. the Thanet rounded the same brig, which was evident to us by her change of course. At 3 h. 6 m., being quite satisfied with our victory,

we commenced to turn round, being at the time within half a minute's run of Cold Harbour Point, which point, in fact, we passed a few seconds later; these odd seconds having been allowed at the time as a compensation for the loss of way caused by turning. At 3 h. 84 m. we had effected our evolution, and were again on our way towards Margate; and at 3 h. 9 m. we met the Thanet coming up. At 3 h. 12 m. the Thanet reached Cold Harbour Point, which we should have reached, as before stated, at 3 h. 7 m. had we not turned a little too soon, thus beating the Thanet 5 minutes in 33, as stated by "Veritas."

It appears from these memoranda, 1st. That the Prince of Wales was tried against the Thanet on the 25th of August; and 2nd, that the statement of your correspondent "Veritas" as to the time is strictly correct; or, in other words, that on the occasion in question the relative speed of the two vessels was in the ratio of 6 to 5 nearly, as proved by the total run, and confirmed by the intermediate observation of the times of passing the brig.

These facts may be explained in any way parties may like best; and it would certainly be cruel to deprive the vanquished party of any construction that may afford them the most consolation; but lest any one should seek the cause in the supposed superiority of performance of the Prince of Wales on that occasion, I beg to inform them that, owing to fresh packings, and other causes, the performance of the engines was that day so much under the usual standard, that the number of strokes never exceeded 30, whereas, with the same diameter of wheel, the engines have often made, in regular working, 32.

After this plain statement of facts, as they came under my own observation, it remains only to be enquired, how Mr. Osmond's " eyes were holden so that he could not see" what must have been visible to the crew and passengers of both vessels, and consequently to himself, if, as he states, he was a passenger on the day in question.

Respecting as I do his straightforward manly way of coming forward with his real name, instead of skulking under an incognito, I hope he will be able to assign a reason why he missed a sight that

to him must have been peculiarly interesting, as it would at once have enlightened him on a subject to which he has evidently devoted much attention. Has he mistaken the day on which he was a passenger? or was he at the time better employed on board?

In either case, I hope he will admit he has been too hasty in contradicting the statement of your correspondent "Veritas, " which (although anonymous) is strictly true, which is more than can be said of the generality of statements to which parties, for obvious reasons, are ashamed to fix their real names. Hoping that his practice and my own, in this respect, may in future be more general amongst your correspondents,

I am, Sir,

Your obedient servant,

Blackwall, Jan. 9, 1844.

JOHN BARNES.

Sir,-Will you favour me with the insertion in your next Magazine of a few words in reply to Mr. Osmond's request for information on the short run which the Prince of Wales and the Isle of Thanet Thames steamers had in August last, as stated in a previous letter of mine. Mr. Osmond will find, if he will take the trouble to enquire, that on the day in question the Prince did not leave London Bridge at the hour he names, say 10 A.M.; but ran down in the after part of the day to Margate, to be ready for taking her station there on the following morning, and was at Grays when the Thanet came up, and gave her a run back to Erith, which was performed by the Prince in 27 minutes, and by the Thanet in 33. It is true the Prince had no passengers, nor had the Thanet a great freight, and Mr. Osmond can make what deduction he pleases on that score. I must further inform Mr. Osmond that it is not greater fitness that continues the Herne running at this season; the interests and desires of the respective companies determine this point; nor will the slightness of build, or weight of machinery, of the Prince prevent her hereafter beating the Thanet. Mr. Osmond is also in error when he states that nothing had been done in the past year for velocity. The fastest boat afloat on the Thames, the Prince of Wales, is the production of that year, and will probably continue to be the fastest until eclipsed by some new sans-pareil. I remain, Sir,

Your obedient servant,

January 9, 1844.

VERITAS.

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ON IRON WATER-TIGHT BULKHEADS. BY C. W. WILLIAMS, ESQ., LIVERPOOL. [From the Parliamentary Report on Steam Vessels.]

A desire to lessen or prevent those accidents to which ships are liable at sea, has long engaged the labours and attention of humane and scientific men; and, when we consider the fragile nature of a ship, as compared with the tremendous force of the sea, and that a single plank is all that is interposed between that element and those on board, we are tempted to express our astonishment, not that so few vessels are lost, but that so many escape.

The casualties to which ships, particularly steam-ships are liable, arise, for the most part-first, from striking against or coming in forcible contact with rocks, or such solid bodies as would injure the framework of the vessel; and, secondly, from accidental collision with other vessels, by which some part of one or both vessels become so damaged as to admit the water to such an extent as to overcome the power of the crews to pump it out.

Ingenious men have endeavoured to devise expedients for lessening the risk consequent on such damage. Among these was the introduction of air-tight tubes to such an extent as, in case of the body of the vessel being filled with water, should give it so large a buoyant power as to keep the vessel afloat. A patent was obtained for this invention, and an ingenious tract published, demonstrating the protection which a given number of tubes, distributed throughout the vessel, would afford. It does not appear, however, that the practicability of stowing away a sufficient quantity of those tubes or air vessels was ever tested, or that a vessel of any magnitude was so fitted as to demonstrate its utility.

That any expedient shall be discovered which will prevent the irruption of the water to an extent beyond what may be within the power of men and pumps to expel is a hopeless case. Even in the event of running on an anchor or other body, which should break any part of the ship's bottom or side, or of a single plank starting, the extent of the injury would most likely be such as to render it impossible to keep the vessel afloat by human power. It occurred to me, that the only practicable expedient for preventing the sinking or actual submersion of the entire vessel would be, by confining the effect of the injury sustained to that portion or section of the vessel in which the injury occurred; and this is the basis of the plan I am now to submit.

Hitherto, nothing has been attempted which could prevent the water, in case of its breaking in, from collision or other causes,

from passing at once throughout the entire body of the vessel; and here lies the great source of danger, particularly in steam vessels, as the fires, being at the lowest part of the hull, are soonest affected by the water; and the chances of escape, by being expeditiously run on shore, are thus lost. Indeed, in steam vessels the mere circumstance of derangement to any of those pipes, or connexion between the interior or exterior, for the necessary introduction and expulsion of water from the engine and boiler, have often caused the most serious results. In one instance, the casual introduction of a piece of sea-weed under the valve of the bilgewater pump of a steam-vessel caused it to fill nearly to sinking. But when it is considered that those casualties, which too often occasion the sinking of a steamer, are local in their origin, and affect but a small portion of the vessel, and that the water admitted is often of so small an extent as to be almost within the power of the pumps, it will at once suggest the importance and the efficiency of the protection, by confining the water to that section of the vessel which has sustained the injury.

The plan of dividing the vessel's hull into sections, each of which should be completely water-tight, has, we are told, been practised by the Chinese in their trade barges, the several water-tight compartments being under lock and key, and appropriated to separate shippers.

This mode of giving security first occurred to me on building the iron steamer, the Garryowen (now plying on the Shannon, at Limerick), and the trade barges which the Dublin Company's steamers tow on that river. Where the hull was of iron, as in the Garryowen, the introduction of iron plate bulkheads was easy and effective; and, independently of the great strength afforded by this internal and sectional bridging, (as it may be called,) these sections were as sus ceptible of being made water-tight as the vessel itself.

Experience has proved that it is impossible to make a timber partition or bulkhead water-tight, or at least that it should continue so. The heat of the vessel is sufficient to cause such a shrinking in a partition of timber planking, as to render it wholly useless in preventing water from passing. Iron plate partitions, however, possess all the requisites for this effectual division of the vessel into so many water-tight compartments. Their introduction into timberbuilt ships appeared, then, an important desideratum, Many objections were, however started. Men do not like to be put out of their way; and, indeed, a plan which should prevent ships foundering at sea was,

at least, not likely to find much favour in the eyes of shipbuilders.

The only parts where water could pass from any one section, when filled, to another section not so filled, would be, not through the iron partitions, but at the sides and bottom of the vessel, where they came in connexion with the frame and planking of the vessel. The preventing the water from passing in this direction is effected by very simple means, viz., by making this part of the vessel solid, that is, without those rooms or spaces which intervene between the frames of the vessel. This solid framing should extend to 18 inches before and after each partition. The mode of effecting this is familiar to all shipbuilders. The introduction of hairfelt between this solid framing and the planking on the outside, and the ceiling on the inside, completes the operation; the plate iron forming the partition having proper diagonal stays to give it strength, and being connected at the sides and bottom with angle iron, accurately fitted to the shape of the vessel, particularly in passing over the kel

sons.

The practicabilty of making these watertight iron bulkheads being established, the next consideration was the number that would be required and their most eligible position. A prima facie view of the case would suggest the greatest possible number of divisions; certainly, the more numerous the partitions are, the more complete would be the protection afforded, and the more the risk of foundering diminished. The only considerations which restricts their number are, 1st, the inconvenience they create by preventing free access from one part of the vessel to the other under deck, the access to each being then, necessarily, from deck. 2ndly, the weight of these iron bulkheads, and the additional timber required to make the vessel solid at the place of junction. 3rd, the expense.

In considering the number and situation of these bulkheads, I will examine the advantages and disadvantages of each.

[Mr. Williams then describes in detail the relative value of one, two, three, or four bulkheads, or partitions, and finally comes to this conclusion:]

We come next to the division of the vessel into five sections, by means of four bulkheads. This arrangement I consider wholly unexceptionable. Besides, this division fell so well in with the business of the several parts of the vessel as to give it at once precedence. The centre section would then be occupied by the engine, boiler and coalbunkers, thus detaching them entirely from all other parts of the vessel. The sections, Nos. 2 and 4, would be the fore and after

holds, or, in case of passengers' vessels, the fore and after cabins; and the two remaining sections, at the bow and stern, need not be as high as the main-deck, as the water never could rise within several feet of the same.

::

Here, then, we provide an effectual remedy against the casualties attending on a vessel coming into collision with another. It may safely be said, that unless the water break into the vessel in all its sections at the same time (and which may be considered impossible), there can be no danger of submersion and experience has proved, that a very small addition of buoyancy would prevent a vessel from sinking after it had been so immersed that the deck was on a level with the surface of the sea. Now, this im- › provement in the construction of steamers is not brought forward as an ingenious theory, or a matter of unascertained efficiency; I merely submit, for general information, what in practice is adopted by the Dublin Company at this moment in all their lately constructed steam vessels, to give security to the public, and protect their own property from casualty or loss.

The model (furnished with partitions on the plan recommended) is illustrative of what may be seen in several of their vessels now at work: the Garryowen, the City of Limerick, the Athlone, and the Royal William; and also in five other vessels recently built by the Company, the Royal Adelaide, the Queen Victoria, the Duchess of Kent, the Prince, and the Princess. To these he has since added the Hindostan, the Bentinck, the Iron Duke, and the Lady Burgoyne.

For testing the efficiency of these bulkheads, and that I might assure the members of the British Association, when in Liverpool, of their having stood the necessary proof, and being practically as efficient as they were satisfactory in theory, I caused the plan to be experimentally tested in the new vessel, the Royal Adelaide, for the inspection of the members of the Association." I first caused this vessel to be bored, and the water to flow freely into section 1, at the bow end. When so filled that the water remained at the same level outside and inside the section, it depressed the vessel six inches at the bow, raising the stern about two inches. Haying the water pumped out, I then had the next bow section filled (No. 2). This depressed the bow twelve inches, without perceptibly raising the stern end. The vessel was then in the situation of one in which collision had taken place. For accuracy sake, I here state that the bow and stern sections are each 16 feet long; the two next, 35 feet long each; and the centre,

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or engine section, 58 feet-making in the whole, 160 feet.

The fact of buoyancy, then, not admitting of a doubt, the whole question of efficiency turns on the practicability of making those bulkheads water-tight; this, then, has been tested in so satisfactory a manner that I do not hesitate to affirm that had the Apollo, the vessel run into and sunk by the Monarch on the Thames; or the Bristol packet, the Albion, run on the rocks in Jack's Sound, near Milford, and many other steam vessels, been appointed with those water-tight iron partitions, no risk of life would have occurred, and the vessels would have remained afloat.

With respect to the additional weight and expense of these iron bulkheads, I would observe that, compared with their importance and the security they afford, they are comparatively insignificant. The bulkheads on board the Royal William and the Athlone cost 2901. each vessel, and the additional timber required in the solid framing must be trifling.

Considering, then, how deeply the public are interested in the progress and improvement of steam navigation, and the rapid strides it is making in all parts of the world, and the multiplication of the risks of collision consequent on that increase, it cannot be doubted that it is a legitimate object for the interference of parliament. Can any rational or humane mind contemplate the consequences of a collision between two vessels, and the loss of life that may ensue, and not admit that they who build a vessel hereafter and neglect such precautions, undertake a responşibility of the most awful nature? the power, I would enforce this protection by law. All vessels, especially such as shall hereafter be built expressly for the conveyance of passengers, should have a licence, granted on inspection and before registration, certifying the insertion of those or other equivalent preventives against sinking.

Had I

[It is scarcely necessary to add, that had the precaution been taken of having this recommendation of Mr. Williams adopted, the following steam vessels would have been preserved, viz.:—The Isis, the Columbia, the Solway, and the Memnon.]/

BEALE'S ROTARY ENGINE. Sir,-In your November Part there is a description of Beale's patent rotary engine, about which (in my ignorance) I wish to ask a few more particulars in addition to the full (?) description given by your correspondent. In the first place, I do not under