it was, consequently, sent across the deserts of Arabia to Egypt by a land-party, who were robbed and detained by the natives. It is needless to add, that the idea of effecting steam communication by the Euphrates line is now totally abandoned on all hands. The mail in question has been so long in coming, that it has been anticipated in its arrival by others of later date, both by the line of the Red Sea, and the old circuitous route of the Cape of Good Hope.

Consumption of Coal in Great Britain.-The quantity of iron annually produced in Great Britain may be taken at 700,000 tons; and the quantity of coal required, at an average, to produce each ton of iron, including that used by engines, &c. may be estimated at 5 tons; giving a total of 3,50,000 tons consumed in the inaking of iron, According to Mr. Kennedy, the quantity of coal consumed in the cotton manufacture, in 1817, was upwards of 500,000 tons, and the manufact re has since more than doubled; so that, allowing for greater economy, we may fairly estimate the consumption of coal in the cotton trade at 890,000 tons a year. Its consumption in the woollen, linen, and silk trades cannot be less than 500.000 tons. The smelting of the copper ores of Cornwall consume annually about 250,000 or 300,000 tons; and it is supposed that the brass and copper manufactures require nearly as much. In the salt-works of Cheshire, Worcestershire, &c, the consumption is probably not under, if it do not exceed, 300,000 tons. The consumption in lime works may, it is believed, be estimated at 500,000 tons.. It would appear, therefore, that the total annual consump tion of coal in Great Britain may be inoderately estimated as follows:

If we suppose that the above sum of 22,700,000 tous costs the consumer, on an average, 7s. a ton, it will be worth, in all, 7,955,000l. a year!-M'Culloch's Account of the British Empire.

Cultivation of Filberts.-Sir, In consideration of the periodical return of the season for trying the merits of the suggestion I inserted in your Number 183, just ten years ago, for improving the crop of filberts, and as I have reason to believe from my own and other's subsequent experience, that my idea is well founded, you will perhaps allow the re-appearance of the following:-" In countries where figs are cultivated to the greatest perfection, particularly in Italy and Greece, a great angmen. tation, both in the size and number of the figs, is obtained by placing on the top of the tree a branch of the wild fig-tree (Caprificus), upon which have appeared male-flowered figs, which are the first to come forth. I have often thought, that the crop of filberts might be both ameliorated and increased, by a somewhat analogons application of a branch of the common hazle, whea covered with the catkins' or flowers. This is just the time to try the experiment." I hope that some of your correspondents who have the opportunity, will try and report

upon the experiment. Besides the increase of the pollen, it may have an effect like the recurring to the original stock by grafting or seed, as with apples and some other fruit-trees. Filbert-trees are often deficient in male flower.-Yours, &c., F. MACERONI.

Colouring Alum Baskets-Query.-Sir, ou referring to the previous volumes of your Magazine, I found a receipt to make alam-baskets, which I tollowed and found to answer. I have tried to colour the alum with the best ingredients dyers use; indigo and cochineal vanished in two or three weeks, and in all my attempts I have found the colours fugitive. Now I shall be much obliged, if any of your numerous correspondents will have the kindness to inform me, and the world (for your Magazine is read by every body), how I can give the alum a permanent colour.-P. B., and a Country Amateur. [P. B. will find a recipe for polishing granite in our 4th vol., p. 228,];

The Practical v. the Poetical. Railway speculators have but little feeling for any thing so unsubstantial as portical association. The Directors of the South-Eastern Railway have just horrified every admirer of the bard of Avon" by advertising, in the most straightforward and businesslike of all possible ways, for a contractor willing to undertake the driving of a tunnel through Shakspeare's Cliff, at Dover, hallowed as it is by the well-known and often-quoted passage in King Lear. Perhaps, after all, it may afford some consolation to reflect, that the present Shakspeare Cliff is identified in fancy only as the one described in the tragedy, and that there will be plenty left quite as high, although none with so peculiar and distinguished an appearance.

New Patent Law Bill.-A Bill " to amend the Prac ice relating to letters-patent for Inventions," prepared by Mr. Mackinnon and Mr. Baines, was to have been read a second time in the House of Commons last night (March 2). We shall give an abstract of it next week; in the meanwhile, we may remark that it is a commission job; and that though it simplities the practice, it will materially increase the expense of Patents.

Errata in the Arithmetical Question of a Town Teacher in No. 706.-P. 400, line 1, after " per annum" read "on the principles of compound interest."

MERRYWEATHER'S PORTABLE FIRE

ESCAPE LADDERS.

"Any fire-escape to be generally useful, must, in the first place, be capable of being carried about without encumbering a tire-engine; and, in the next place, must be of instant and simple application."-Braidwood on Fire-Escapes.

"The escape best adapted to accomplish so desirable an end should be simple in the extremeflexible and portable-ever ready at command, and capable of being applied at the back of a house as well as in the front."-Wivell's Lecture on FireEscapes.

Sir,-In consequence of the melancholy and fatal fire in Tottenham-courtroad, in December, 1835, at which four lives were lost, and several other persons narrowly escaped a similar fate, the inhabitants of the south-western district of St. Pancras formed an Association for providing and maintaining a fire-engine and a sufficient number of fire-escapes, to guard that populous neighbourhood, as far as possible, against the calamitous effects of fire. The gentlemen who were appointed Trustees and Committee upon that occasion, discharged the duties imposed upon them with great zeal and judgment, and they have the satisfaction of knowing that the example set by their neighbourhood has called forth a similar generous feeling in other parts of the metropolis; several parishes have sought the benefit of their experience, and by their advice have adopted similar precautionary measures. From present appearances, the beneficial results of these endeavours seem likely to be permanently diffused throughout the country. At the commencement of their labours, the St. Pancras Committee invited inventors to come forward by public advertisements. The models and plans that were in consequence submitted to the inspection of the Committee, were so exceedingly numerous as to render the task of examining and deciding upon their respective merits one of a very long and difficult character. Many extremely meritorious inventions were not available on account of expense of construction, and want of the requisite portability.

The result of a most careful comparison and investigation was the selection of two escapes, as being most unquestionably the best of the number submitted. These were the spar fire-escapes of Mr. Ford, and the portable fire-ladders of Mr. Merryweather. The former invention I have already fully described at page 130 of your 25th volume, and I

now propose to explain the peculiar merits of Mr. Merryweather's ladders, which have already been several times adverted to in your pages, during their progress towards their present perfect

state.

The formation of a society for the protection of life from fire, in March last, has led to several further investigations into the relative usefulness of all the various methods of escape from fire that have been proposed from time to time by different individuals, which has had the effect of bringing forward several new, as well as of establishing the originality of many old, inventions. The ultimate result of all these inquiries, however, has been a confirmation of the choice made by the St. Pancras Association, and the establishment of the vast superiority of the two inventions they had adopted. One of the earliest parishes that availed themselves of the experience thus gained, was that of St. Andrew, Holborn, who have twelve fire-escape stations under the superintendence of the Police. Besides these, Mr. Merryweather's ladders have been adopted by the parishes of Allhallows, St. Sepulchre's, Greenwich, and several others; by the towns of Carlisle, Hartlepool, Maryport, Monksilver, Richmond, Windsor, &c. They have also been supplied to the City of New York, to the London, Sheffield, Shrewsbury, and several other provincial fire-offices, as well as to numbers of the nobility and gentry, including the Emperor of Russia, His Grace the Duke of Devonshire, Lady Greville, and others.

What the positive requisites for an efficient fire-escape really are, is a point upon which all parties have long since been pretty well agreed; they are, economy in the original cost, portability, simplicity of construction, and management; and, finally, facility and universality of application. All these qualifications preeminently characterise the invention now under review, and its facility and universality of application gives it a decided superiority over every other machine.

Mr. Merryweather's apparatus in its complete state consists of six separate ladders, each six feet and a half long, all precisely alike, each fitting into one another in whatever order they may be taken. One of the ladders, which is always the first to be raised, is furnished at the top with a pair of small iron wheels,

which considerably diminish the labour and facilitate the raising of the ladders, by running over irregularities and projections in the wall, that would otherwise seriously impede their ascent.* In the middle of the wheel-axle a small brass pulley is suspended by an universaljoint; through this pulley a rope is passed, having at one end a strong leather belt and buckle, the length of the rope being wound round two iron hooks placed on the right-hand side of the ladder.

In the accompanying drawing, a set of these ladders are represented as applied to a dwelling-house from which an escape is to be effected; four lengths have been joined up and raised, forming a ladder of sufficient height to allow persons to be lowered by means of the escape-belt from the second-floor window; while the other

Although I was the first person to suggest and advocate the employment of these wheels, it is but justice to Mr. Merryweather to state, that the idea was furnished by his escape of 1830.-Vide vol. xiii. p. 290.

two lengths form a communication with the balcony.

Fig. 2 shows the uppermost ladder upon a larger, and therefore upon a more distinct scale. aa are the two iron wheels, with feather edges to prevent the ladder from slipping sideways; b is the pulley, and c the escape-belt; de are two strong iron hooks, round which the rope is coiled. The lower hook e, is fixed, but the upper one d is moveable, turning upon its centre, and having a joint nea the ladder. While the hook is turned upwards the coiled rope is held firmly in its place-but as soon as it is turned round, the joint allows the hook to fall, and the rope being disengaged is thrown down into the street. Fig. 3 shows the hook in this position. Three men are sufficient to raise a set of these ladders, in doing which, two of them place themselves inside the ladder, with their backs about three feet from the wall; each stooping, takes hold of the lowest step with one hand, and the side of the ladder with the other, and raises the ladder till their arms are perpendicular; the third party then places another ladder, narrow end uppermost, upon the ground as nearly as possible in a line with the lengths already raised; the two men then drop the ends of their ladder into the iron sockets, when the joint is made; they then stoop, again raise the ladder, and so on, till the necessary height is attained. By bevelling off the outer ends of the ladders, and making the iron sockets to correspond, Mr. Merryweather has greatly facilitated the joining, and at the same time made the ladder much stiffer than those formerly constructed. The ladder having been run up between the windows, it is shifted until it is over that from which an escape is to be effected; the fireman then runs up the ladder, turns round the hook which throws down the rope, and seizing the belt enters the window; having fastened it round the waist of a person, he puts them out of the window, while those below holding on the rope affords a safe and easy descent. The belt being unbuckled, is drawn up again, until all the inmates have been extricated. Mr. Merryweather has very judiciously adopted the belt in preference to any seat or cradle, as being more portable, more secure and much more expeditiously applied; it is of sufficient

strength and capacity to lower two persons at the same time.

With reference to portability, I may observe that a complete set of these ladders can be carried and elevated by three men; four lengths, which will reach most second-floor windows, are within the power of two men. These ladders can

be taken through the narrowest passages, or even through houses, and raised in a very small space. The average time of raising six lengths, is twenty-one seconds

I have seen them raised in seventeen! Four lengths have been raised to a second-floor window, and six persons brought down, by means of the belt, in one minute and a half!

A great advantage of these ladders is, that no more than the length actually required has to be raised ; in nine cases out of every ten, four lengths will be found sufficient.

The stability and safety of long ladders thus formed, is proved by their being in constant use by the firemen, at fires and in ruins. Although not in the habit of mounting ladders, I have ascended and descended both by the ladder, and the belt from the roofs of high houses, with the utmost confidence.

This apparatus is of universal applicaion, and so simple in its construction and management, that no person, however ignorant, could feel at a loss how to use it in case of need; it has been the subject of repeated commendation by the public press, and fully bears out the character they have given it, of being "the simplest and best known external means of rendering assistance to persons in case of fire."

I remain, Sir, yours respectfully,
WM. BADDELEY.

London, Feb. 20, 1837.

COMPOSITION AND DECOMPOSITION OF

MATTER.

Sir,-Amongst the many scientific writers in your Magazine, I do not find that any have given much of their attention to chemical subjects, although there is probably no department of physical science in which a more extensive or more interesting field is laid open for speculation and debate. I regret this,

for, living as I do almost out of the reach of scientific information except what I can occasionally gather from periodicals &c., I should be glad to see these matters, in which I feel a peculiar interest, discussed in your pages. You will, doubtless, have foreseen already, that these observations are intended as a preamble to others, for which I am to beg insertion; but I hope you will not, on that account, refuse to let me occupy a small portion in your next Number, particularly as I do not often trespass on your pages.

The question concerning the constitution of matter which for upwards of 3000 years agitated the learned world, has now assumed a settled appearance; and there is rarely to be met with a person who will refuse his belief in the existence of "ultimate atoms combining in definite proportions," so beautifully has the theory, which our illustrious countryman, Dalton, has the honour, the imperishable honour, of having first proposed been developed, and so universally applicable have the laws been found, to all the tests to which they have been applied. But though the fact, that matter consists of ultimate atoms, is established, as far as reasoning can establish it, there still remains the difficulty of understanding the nature of that bond of union, by which two particles, or atoms of dissimilar substances, are united together, and made to lose their characters, both physical and chemical, as individuals, and to assume such a totally different character as a compound. We take a certain quantity of two invisible gases, present them under certain circumstances to each other; they disappear, and a fluid results, which on examination proves to be water; we take this water, act on it in a certain manner, in its turn it disappears, and is resolved into the same two gases as before :- - the inference is a natural one water is composed of two substances which when insulated are invisible, and bear an immense ratio in volume to the result of their combination. But can we trace in water any character similar to that possessed by oxygen or hydrogen gases? No! water then consists not of oxygen and hydrogen gases, but of oxygen and hydrogen, and the mystery seems to lie in the meaning of the term gas. Gases are generally de