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was given to one of them by a lady's-maidancient prejudice-when he must be taught who said it was brought from Paris.

to place his trust in walls of other stuff than Mr. Girdlestone and Mr. Metcalf moved wood-when, if he would have his “mefor the injunction ; and Mr. Richards and

teor flag" brave for another “thousand Mr. Wood opposed.

years” the “battle and the breeze," he His Honour said, he felt some difficulty

must build his floating towers of a more about granting the injunction, because he

impregnable material, than any which his could not but think there was a substantial

native forests have ever produced. difference between the thing that was claimed by the plaintiff's specification, and what the

It may perhaps serve to procure from defendants had been making. It was not

the old gentleman a more patient hearing for him now to pronounce an opinion whether

for the subject matter of our present the patent was good or not, but he thought discourse, if we state at once that there there was a sufficient difference between the is nothing outlandish-nothing French, articles manufactured by plaintiff and de especially-in the material proposed for fendants to justify the Court in refusing the his adoption, and that it has as good a injunction, and directing the plaintiff to claim by right of birth to his favour, as bring such action as he should be advised, his ancient oaks themselves. All that is to establish the validity of his patent, with required of him is to build his ships of liberty to either party to apply to the Court. iron instead of wood-of iron, the pro(We pointed out the untenable character of

duce of our own mines, and the industry this patent at the time it was specified. See

of our own people—made from native Mech. Mag. vol. xxxiii. p. 445. En. M. M.]

ores, with the aid of another of our native products, coal—and both the iron

and the coal being things which we posIRON SHIPS.

sess in greater abundance and can proThe most venerable, the most deep- duce cheaper than any other nation on rooted, and by far the most respectable the face of the earth. of all our national prejudices, is that The use of iron for ships is commonly which every person of English birth en supposed to be of very recent origin, but tertains in favour of the “ Wooden Walls

Mr. Grantham, the author of a work on of Old England.” Identified as they are the subject which has been just

published, with our noblest triumphs as a people, and is by far the best on it which has yet with centuries of inviolability at home and appeared, shows that its value as a mateof conquest abroad—it is not to be won rial for ship-building has been known for a dered at that we should love them dear.

great many years, during which it has been ly. The “good old times" have handed making sure though slow progress towards down to us nothing that we venerate its now fast-extending popularity. Forty more, if indeed so much.

Even our

years ago boats of iron were known upon rights and liberties--yea, the very mon

and some of this description were archy itself-may be said to have always lately cut up, which had been twentyheld but a secondary place in our regard. eight years in use. The first iron vessel We have put up with tyrants and done with that ever put to sea was the steamer out kings, but never has the idea once Aaron Manby, built by the Horsley Iron entered into the national mind of dispen Company, for the Seine, and named after sing with our wooden walls." Of no its spirited projector. She was completed common wood, too, are these same walls in 1821, sent to London in parts, put to“ hearts of oak” every one, and of sound gether in one of the docks, and navigaold English oak the best of them. Loved ied by no less a person than Captain (now they are, not only for what they have Sir Charles) Napier, from London to done for us and for our forefathers, but for Havre, and thence to Paris, being, says their own sakes, as (mostly) natives of Mr. Grantham, " the first and only vesthe same sea-girt soil, and partakers of sel of any description that ever went di. the same illustrious fortunes. England's rect from London to Paris."(?) Mr. glory and safety, and England's wooden Manby built subsequently three other walls are so intimately mixed up together iron steam-vessels for the Seine-one at in our memories and affections, that to separate in our thoughts the one from the

• "Irou as a Material for Ship-building, being a other is found next to impossible.

Communication to the Polytechnic Society of Liv. The day is at last come, however, when erpool - By John Grantham, C. E., President," 96

pp., 8vo, with numerous plates. Simpkin and Co., John Bull must be reasoned out of this and Weale, London.

canals;

the Horsley Iron Works, and the two Great numbers of iron steamers are now others at his own works at Charenton, in plying on the Thames (where the prinFrance. The whole of these vessels are cipal builders are Messrs. W. Fairbairn understood to be still at work on the and Co., and Messrs. Ditchburn and Seine. Mr. Manby states, as of his Mare,) the Mersey and the Clyde, and own knowledge, that from 1800 to 1822, on nearly all the continental rivers. Some the hull of the Aaron Manby never re;

of a larger and stronger description are quired any repairs, although she had regularly employed in making sea voyages been repeatedly aground with her cargo with heavy cargoes.” The iron steamon board." The next iron steam-vessel ers running between Liverpool and Glasmentioned in Mr. Grantham's retrospect, gow, and built by Messrs. Tod and Macwas built, under his father's superintendo gregor are well known. Of these the ance, by the Horsley Company for the Princess Royal is the largest, being up: Shannon navigation in 1824-5; “ Since

wards of 800 tons. She is a fine vessel then she has been constantly at work, and of immense power, and is unequalled in is now in good condition.”

speed as a sea-going steamer.'

" Iron “This vessel was the origin of the exten

vessels also are now fighting our battles sive and spirited company which now occu

in the East, among which, the Nemesis pies that splendid river, and which is con.

and Phlegethon, built by Mr. Laird, ferring important benefits on the large tract

are entitled to particular notice from the of country through which the Shannon flows. prominent part these vessels have taken My friend Mr. Williams, managing director in the Chinese war." "Of iron-sailing of this and the City of Dublin Steam Packet vessels, some have made voyages, both Company, at this time directed his attention to the East and West Indies." “ The to the subject of iron vessels. With his Ironside was the first iron-sailing vessel usual discernment he foresaw the advantages of any magnitude that was employed for to be derived from this source to steam sea voyages, and she has been highly suc. navigation, and has ever since been a steady cessful.” The Great Britain, now buildadvocate of the principle. It was at his re ing at Bristol, and better known as the commendation that the Shannon Company Mammoth-the completion of which the continued to construct iron steam-vessels,

scientific world is truly stated to be await. and there are now six at work, all in excel. lent condition, two of them in salt water."

ing with intense interest --is to be all of iron. To these historical particulars

we must not forget to add, that Mr. Mr. Grantham's notices of the subse. Grantham himself engaged about three quent progress of iron ship building do

years ago very extensively in the build. not follow in very regular order, and are, ing of iron vessels in partnership with on the whole, extremely incomplete, but, some other gentlemen, (under the firm of such as they are, we give them as they Messrs. John Grantham and Co., of Lipresent themselves.

verpool,) and is therefore well qualified Iron vessels now began to attract the at by special acquaintance with the subject, tention of those who were engaged in river as well as by general scientific attainand canal navigation, and several were ments, to write upon it with advantage to built in this country and on the Continent.

the public. “ The first that were built in Liver. The advantages which iron vessels pospool were undertaken by Messrs. Fawcett sess over those of wood, are treated of and Co., and under the superintendance by Mr. Grantham, under the heads of of Mr. Page." “Shortly after this time Strength and Lightness. Mr. John Laird, of North Birkenhead, Capacity for Stowage. commenced building them on a large scale, Safety. and has since been extensively and suc Speed. cessfully engaged in this pursuit. Mr. Durability: Fairbairn, of Manchester, also very early Economy in Repairs. took an interest in iron vessels, and was Cost. a party to a series of experiments made Draught of Water. at Glasgow, in which iron vessels were And in every one of these respects, he employei.” * Many others have now proves clearly and satisfactorily, that iron commenced the business, and numerous vessels have decidedly the advantage. iron steamers, and iron sailing vessels of We select for exemplification, one or two large tonnage are nuw afloat or building. striking passages.

p. 8.

POSSIBLE MAGNITUDE OF IRON VESSELS. small sections, affording the strongest sup“The great strength of malleable iron to

ports directly opposed to the strains that

tend to disturb the form of the plates, and resist strains in every direction is well known;

in the direction in which they can least resist but, to those who are not conversant with

such strains. The sides between these decks the subject, the extent to which this advant. age may be carried is not at first apparent;

and bulkheads would be strengthened by the or how the material may, from comparatively

ordinary mode of framing. In addition to small pieces, be so combined in large masses,

this, the lower part of the vessel might be as to form the ponderous body of a ship;

again intersected by longitudinal divisions; and they are thus too apt to prescribe a limit

and these decks, bulkheads, and subdivisions to its use. An opinion, indeed, is now very

would not only be securely fastened to the

shell, but to each other,--the whole thus begenerally entertained that iron may be suitable for small craft, but is inadequate for the

coming a mass of almost irresistible strength, construction of vessels of heavy burthen.

meeting the strains in whatever direction This, however, is a sopposition so erroneous

they might arise, while, at the same time the that the reverse would be much more cor

weight would be far below that of a timber rect; for large vessels will afford the best

vessel of only moderate scantling, and the practical demonstration of the superiority

room for stowage would be much greater." of iron for ship-building. In the application

DURABILITY. of timber, obstructions increase in a ratio proportioned to the increased size of the yes.

" Where, I would ask, in the catalogue of sel to be built. How often has the ship

objections, real or fancied, to iron ships, is builder the greatest difficulty in obtaining

there one to be found equal to that dreadful timber to suit the varied curves of our finest

scourge to wooden vessels-the dry rot; the ships ! How often is the country despoiled shipowners to require any lengthened, re.

effects of which are too well understood by of its noblest ornaments by the tempting

marks from me? No age has been without prices he is compelled to offer for its most magnificent oaks, the largest of which are

its nostrums, its quackeries, and its • in

fallible remedies for the dry rot, and frequently insufficient for his purpose! How are his brains racked, and his patience tried,

no period has been so productive of them

as that in which we live; but, from all I can in seeking for crooked timber necessary to frame a sharp floor, or a square bilge! How

perceive, this plague is as prevalent as ever. often is he obliged, though he knows it to

A circumstance which has recently fallen be injurious, to scarf the frames, for which

within my observation is strongly illustrative

of this subject, as involving the comparative no timber can be found sufficiently large to

merits of wood and iron. On removing the enable him to avoid such defects! And is not

timber-work of the John Garrow, preparathis one cause, amongst others, why our building yards are empty while our ports are

tory to the alterations determined upon in filled with ships from other nations, in which

that ship, we find that the dry rot had altimber is more plentiful and the choice more

ready (though she was not three years old)

begun its work of destruction. That part of extensive!

the lower deck which had been laid some “ But how stands the case when we turn

time after she was launched had become de. to iron ? Where is the frame, even of the most intricate form, that our smiths cannot

cayed, and all the timber not exposed to the

air was more or less affected. The iron, on mould? Where the frame or beam so large that iron cannot be found of which to fashion

the contrary, though it had been exposed to

a fourteen-months' voyage, without being it, and that, too, if need be, without a scarf ? Here there are no knots, no sap, no cutting tisfactory state.

either cleaned or painted, was in a most sa

Not only were the plates across the grain. Here there is no useless

and frames free from any perceptible injury, timber, placed merely to fill in, or to cross

but the edges of a number of square boltbuts. Here every inch of material is of

heads, in and about the rudder, still retained service, and every scrap applied to some use

their sharpness, and appeared to be perfectly ful end."

free from corrosion. The dry rot in wooden

ships (which finds no parallel evil in those of “ If we view the subject with respect to iron) is frequently as remarkable in the ear. very large vessels—ships of the line or first liness of its commencement as it is invariably class steamers, in which intermediate decks rapid in its progress, and no appliance biare not only not objectionable, but requisite therto resorted to has, in all instances, been for the guns and stores, and in which entire effectual to avert its insidious development, or partial bulkheads may be multiplied with. or to arrest its destructive progress. How out causing much inconvenience - we have many stately vessels are now mouldering in iron the means of dividing the shell into away under this destructive visitation, while

*

their fine and graceful forms conceal the that, were it not superfluous, many pages treacherous enemy within !"

might be filled in recording them.

“ The Nemesis, war-steamer, ran on one ECONOMY IN REPAIRS.

of the Scilly rocks in the British Channel “ The wear and tear of iron vessels (and I with such violence that, to use the expresspeak confidently froin actual experience) sion of my friend Mr. Claxton, the harbour are practically trifling, and the repairs are master of Bristol, if she had been of wood consequently light. This item, which in she would most probably have left her bones wooden vessels presses so heavily on the there. The damage she sustained by the profits, is, in iron vessels, of but slight im shock was, however, so trifling, that she was portance; and although the comparison will navigated round to Plymouth, where the rebe found very favourable in iron sailing ships, pairs were easily effected for about 301.the fact will be more clearly shown by reference to steamers. The usual calculation

Nor is it solely on the ground of the for a timber-built steamer is, that the expense

intrinsic superiority of iron over wood, of repairs will, in ten or twelve years, have

that the case in favour of iron vessels equalled the first cost. In a well-built iron

rests. The universal adoption of the steamer repairs will not, I believe, have be

new material is recommended by other come necessary within that period, provided considerations, which, if iron were only the vessel has not been injured by accidents; as good as wood, ought to command, for and, under any circumstances, I feel con. them, the preference. Mr. Grantham cal. fident that it will be more expensive to keep culates that it requires the constant occuin repair the copper sheathing alone of a pation of about 400,000 acres of land, wooden vessel, than to effect the whole re

on which to grow the timber for the ships pairs in the hull of an iron vessel.

annually built in this country and in our “ I revert to canal boats as furnishing a

colonies ; and he proceeds to show, how, fair demonstration of the comparative merits

by the adoption of iron, not only would of wood and iron. My informant in this

all that vast quantity of land be set free point states that iron vessels are kept in repair at very little expense, but that wooden

for the production of human food, but a boats, when four or five years old, begin to

new and most extensive source of probe very expensive; as much so, indeed, in

fitable employment for our people be one year, as iron boats will in three or four, opened up.

He mentions boats which he “ So much of the timber tbus employed knows to be ten or fifteen years old respec as is grown in this country occupies a protively, and which are still in excellent con portionate amount of land that would other. dition. I know of some,' he says, 'that wise be appropriated to agricultural purposes; have been at work upwards of eleven years, so much of it as is not grown here, takes and have not cost more than 21. each during our capital, to a certain extent, out of the all that period.' Messrs. Tod and M'Gre country; but, worse than all, our people are gor, of Glasgow, in writing on this subject, deprived of profitable and extensive employsay,– Some of the vessels we built were ment by the inducement to build ships in not in dock, or on a slip for four years : their those countries where the material is most bottoms were never seen, yet when examined abundant. By the evidence of Mr. Meek, they were found to be as entire as on the day who was lately commissioned by government they were launched. The hulls of some of to enquire into the state of trade on the our iron river steamers have not cost 11. each continent, in relation to this country, we these five years. Knowing their stability, learn that it is impossible for our ships to we are very anxious to get sea-going vessels compete in freight with those built by several of iron introduced. The Royal Sovereiyn other nations, owing principally to the comwas, we believe, the first regular sea-going paratively low rate at which they can proiron vessel in this country. The first six cure the materials for building. Notwith. months she ran 25,000 miles under great standing the great sacrifice now being made disadvantages, she having to encounter dark in the revenue of this country, by the reducnights and low water in coming up the tion of duty on foreign timber, and the conClyde ; yet during this time lost not one trip, sequent decrease that will probably be made but was punctual to the time advertised.' in the price, the foreigner will still have an

“ In the event of accidents, the repairs of advantage over us in having the material not iron ships are extremely light, and in this only considerably cheaper, but at his own respect also they bear a most favourable door, while our supply will necessarily be comparison with wooden vessels. The cases precarious. that have fallen within my own observation are so numerous, and so decisive of this fact, " But let iron become the material with

or even more.

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which our ships are henceforth to be built, and the whole question assumes a widely different and highly cheering aspect. Without being in any degree dependant on foreign countries, we should find an inexbaustible supply of more suitable and less perishable material for the whole of our national and mercantile marine in our own country; from this source our iron-masters would have a fresh and a steady demand for their iron; and an increased demand for labour, both at the mines and in our building yards, would be the immediate and invaluable result.”

Mr. Grantham investigates also the principal causes which obstruct the progress of iron ship-building, and finds the national prejudice, of which we have before spoken, and some other prejudices of a more vulgar cast, to be at the bottom of most of them. The supposed difficulty of steering iron vessels by the compass, he considers to be a fair ground of objection; but this also is most satisfactorily disposed of.

HOW TO REGULATE THE COMPASSES OF

tion, and the commander having discovered its extent, makes allowances for it in his cal. culations. The compasses in iron ships are, however, so accurate, after being corrected, as to be free from any sensible error.

The power of the magnets, and the intensity of the magnetism of the ship, will probably alter by time; but I have not heard that this effect has yet been observed on any compasses that were well corrected. A care. ful navigator would, however, soon observe any deviation that might arise in them, and on his return to port have them again corrected; as iron vessels become more general, some one will be found in each port capable of performing this operation with sufficient exactness for all practical purposes."

The Construction of Iron Vessels is treated of in great detail under the diferent heads of --Keels-Stem and Stern Posts—Floorings - Side Frames-Gunnels — Plating — Jointing – Single and Double Rivetting - Deck Beams and Bulkheads -- and on all these matters, much valuable practical information is communicated.

The following statement of the proportions observed in the building of the Great Britain (late Mammoth) and other particulars respecting her, furnished to the author by Mr. Guppy, the Managing Director of the Company to which she belongs, will be read with interest.

The Great Britain. “ Her dimensions are truly gigantic ; they are as follows:

feet.
Length of keel ...........
Length from figure head to tafrail...... 320
Beam...

51
Total depth from underside of the up-
per deck to the keel

31 4 in. Draft of water when loaded................ Tonnage, per old measurement, about 3500 tons. Displacement of water when drawing 16 feet, about

3000 “The plates of the keel are from fths of an inch thick in the middle, to 1 inch at the ends; and all the plates under water are

IRON SHIPS.

" When the Ironside was ready for sea, Professor Airy came to Liverpool and made a series of observations upon her, with a view to the correction of the local attraction of the ship. This object he effected in the most satisfactory manner ; and not the less so that the plan he adopted was exceedingly simple. Mr. Airy afterwards, with great liberality, published in the United Service Journal a list of rules, by observing which, any one might correct the compasses of iron vessels, without difficulty.* This system is found to be so efficient, that when applied to iron vessels the compasses are generally more correct than those in vessels built of timber. Few ships are free from some local disturbing infuence; but it is not considered to be so great in wooden ships as to require correc

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16

• The operation may be shortly described as follows:-Having fully completed the equipments of the ship, especially as regards the iron work, and having deterinined the exact position in which the compass is to be placed-take a point on the deck exactly under it through this point describe two lines on the deck, one parallel to the keel and the other at right angles with it. Provide two powerful Inagnets, about 2 feet long, and a small box, 7 inches long by 3 wide, full of small iron chain, or small pieces of iron, laid in different directions. The vessel, being in a wet dock, should be firmly moored by four hawsers, and her head being made to point exactly to the magnetic north, as ascertained by a delicate azimuth compass on shore, an observation should be made. The needle will now probably be found to be very incorrect: one of the magnets should then be slipped along the athwart ship line, either over or under the deck, till the needle points correctly. The ship's head may then be turned due

east, and the other magnet, being placed on the fore and aft line, is so regulated that the error, if any, in the needle, is corrected in this position also. The vessel should then be moved round to all the four points, north, south, east, and west, and any error now observed may be corrected by again changing the position of the magnets It is now necessary to point the head of the ship towards the north-west, or south-east, and any deviation that is observed will be corrected by the use of the small box of chain, the exact spot for which must be determined by trial. These corrections carefully attended to will cause the compass to be free from all sensibie error. The magnets should be of the best description, and be placed in a box full of tallow, which box may be nailed to the deck or the ceiling of the cabin.

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