under one master mind, has enabled the fire-offices to avail themselves to the utmost extent of the suggestions of practical men, for improving their present machinery, or of introducing any thing new that possesses superior advantages. During the past year a great number of minor improvements have been made in the accoutrements and discipline of the men, with a view of rendering them pre-eminently efficient, both in the preservation of life, and the protection of property. Additional sets of scalingladders of improved construction have been provided, and the men have been frequently exercised in raising and joining them; in which some have become exceedingly expert. I have seen some crack hands at the head station in Watling-street, join and raise seven lengths, forming a ladder upwards of forty feet high, in twenty seconds! These ladders with the improvements made by Mr. Merryweather, engineer, of Longacre, form the simplest and best external fire-escape yet known," and have been extensively adopted by several of the principal metropolitan parishes. Sheets of canvass, with leaden weights to steady them, have been carried by the engines to cover the gratings of drains, to prevent the escape and waste of water. The senior firemen have been armed with short axes, having a cutting and a ripping end, which are worn in leather sheaths affixed to the belt; the junior firemen carry a canvass bucket strapped on their back During the year, my long despised portable-dams have been in constant and successful employment; thereby enabling the firemen to get the engines into full work, the instant water is obtained.

At the beginning of last year, at my earnest request, Mr. Braidwood provided his engine in Watling-street with a pair of moderate sized lainps, furnished with strong reflectors, in lieu of links which had previously been employed. These lamps have one tongue at the side and another at the back, so as to fix upon the engine and throw a light forward while travelling, or backward while the engine is at work; or they can be hitched on to a fireman's belt, throwing a distinct light before him wherever he goes, while, at the same time, both his hands are left at liberty to do whatever

is required. It has been a practice from time immemorial, to use links at fires, but they are exceedingly objectionable; they occupy one of the fireman's hands, soil the engines and clothes of the firemen and others, and are continually dropping fire about wherever they are carried. The new lamps first came into use at a large fire in Trinity-yard, Leather-lane, on the 3d of February, and were at once found to be so useful, that all the Establishment engines were immediately supplied with them. The greatest novelty, however, is the introduction of the smoke-proof dress, of Lieut.-Colonel Paulin, commanding the corps of Sapeurs Pompiers, in Paris. M. Paulin, having fully established the efficacy of this dress by actual experiment, it was submitted to the committee of managers of the London Fire Establishment, when Mr. Braidwood tested it with the same successful results as M. Paulin obtained; all of which was done, by-the-bye, eight years ago by our countryman DEAN.

The accompanying drawing (see front page,) represents a fireman equipped with M. Paulin's dress, which is made of leather, and is a kind of hood which reaches down about the middle, being there fastened to by a belt. The wrists are secured by strings. Two glass eye-pieces afford uninterrupted vision to the fireman. A small leather hose is attached to the back of the dress, through which a supply of fresh air is continually forced by the working of an engine, or what is better (as in Mr. Dean's apparatus), by a pair of small bellows. The air thus thrown into the dress is always escaping in small quantities through any crevices that may occur at the middle or at the wrists, thereby preventing the entrance of smoke at any of those places. A lamp is attached to the belt, to which air can be supplied from the dress, when the atmos phere in which the fireman is compelled to operate, is so vitiated as to be unable to support combustion. A whistle is affixed just opposite the mouth, by which the wearer can give any preconcerted signals. The first employment of this dress "on actual service,' "took place at a fire in Basing-lane, on the 22d December, as mentioned in your " Notes and Notices" at page 272, which was the first opportunity that presented itself,

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after the experimental trial in August last, when the positive efficacy of the apparatus was satisfactorily established.

The opportunities of applying this dress with advantage, are not, perhaps, so numerous as many persons imagine; but whenever the circumstances occur to which it is adapted, the advantage of its employment are immense. In all cases of fire in vaults or cellars, or in confined places where sulphur and various other per nicious substances are deposited, or in the holds of ships, &c. this dress is invaluable.

"

Having for fourteen years attentively watched the progress of the firemen, under the old state of things-and for four years the results of the united system, I have no hesitation in most positively asserting, that both the Insurance companies and the public generally are gainers by the change. Perhaps, among the numerous points of difference which distinguish the two systems, the most marked is the mode of treating fires generally; under the "old system,' the firemen were as prompt in their attendance as their imperfect arrangements would admit, but on arriving at a fire they began to make the most diligent inquiries about insured or not insured, and on discovering any property in which their own particular office was interested, they did their utmost to extricate it as much as possible from the flames -this done, their attention was given to their engine, the fire in the mean time raging with almost uncontrolled fury. To this practice alone, we are indebted for the spread of many a fire, which by ordinary attention might have been stopped at a very early period of its career: this circumstance had much, very much to do, with the extent of the lamentable fire at New York in December 1835.

The firemen of the present day, in this metropolis, make no attempt to extricate property, but apply themselves immedi. ately, with all their skill and energy, to the suppression of the fire; by which means they most effectually save a large amount of property, which, under any other mode of proceeding, would be destroyed, in eight cases out of ten extinguishing the fire in the apartment in which it be gins. As soon as the fire is safely put out-but not till then-inquiry is inade to know if the property damaged is insured or not, for the purpose of apprising

any parties who may be interested therein. By this proper course, the uninsured, the insured, as well as the insurers, all equally receive the greatest possible protection. The advantages, arising from this cause, are increased by the particular mode of dealing with fires introduced by Mr. Braidwood, viz. fighting them at close quarters; aided by the opportunities of doing so, from extraordinary promptness in arrival and getting to work, afforded by the arrangements of the fire-engine establishment.

The firemen, now, never depend upon gratuitous aid at fires; all persons who volunteer their services to work the engines, are paid for their labour at a fair rate, besides being furnished with a proper quantity of refreshments. The military and police when thus engaged, are remunerated like strangers. By this satisfactory arrangement, the engines are always well manned and worked with the greatest spirit, enabling the firemen to devote their undivided attention to the skilful application of the excellent jets of water thus placed at their command.

A floating fire-engine of great power is in course of completion, capable of being worked by one hundred and fifty men, though ninety is the regular complement. It will be stati ned as near Southwark bridge as possible, and some very judicious regulations have been made to ensure a prompt and effectual method of bringing this valuable auxiliary into action, wherever its powerful aid can be employed.

From the statement made at the commencement of this report, it appears that in five hundred and thirty-one instances, out of five hundred and sixty-four, the fire has been fairly beaten by Mr. Braidwood and his brave corps, even in the very building where it first began. This has been no easy task, nor has it been attended with any ordinary kind or degree of danger; nevertheless, it is with unfeigned pleasure I state, that no serious accident has happened to any of the firemen in the execution of their duty. Numberless contusions, and so forth, many of them inflicting much suffering, have unavoidably been encountered; but no loss of "life or limb" has this year to be recorded.

I have been an eye-witness to the bravery, the skill, and the patience of the

A FEW WORDS ΤΟ MR. MACKINTOSH

AND NAUTILUS.

Sir, I stated at the conclusion of my last letter (No. 697), that I had not then made up my mind whether I should answer Mr. Mackintosh's letter (No. 698). In that communication, his method of accounting for the moon always presenting the same face to that of the earth, seemed to me so repugnant to every known law of nature, that I could hardly imagine that he was in earnest. But, from his reply to Nautilus (No. 701), it appears that he was perfectly serious; and, strange to say, he seems to infer from my silence, that I must be a convert to this part of his theory. He states, "I was not ignorant of this when I made the assertion, that the moon does not revolve upon her axis, nor do I see any necessity to withdraw or qualify that assertion from what has been advanced by Nautilus. Kinclaven also objected to the same assertion, but the parallel case of the wheels, and leaden balls, at once enabled him to perceive that it had not been made unadvisedly," &c. Indeed, Mr. Mackintosh, you very much deceive yourself if you imagine, that because I did not reply to this, I have become a convert to that strange part of your electrical theory. Although some such notions as you have promulgated, about the leaden balls and fly-wheel, you may have seen represented in some orreries, surely you cannot be indebted to these artificial toys in attempting to upset what in reality takes place in the laws of nature. I shall make another slight attempt to reclaim you, Mr. Mackintosh, although I am much afraid you are past redemption.

If a body is perfectly spherical and of uniform density, and if it were projected forward, there could be no reason assigned why it should revolve upon one axis more than another; or, indeed, why it should revolve round any axis. But if this is not the case, it is well known (or ought to be known), and can be demonstrated from a combination of mechanical and mathematical principles, that it must revolve round an axis. A stone thrown from the hand always revolves round its axis; a cannon-ball, or bomb-shell, has often such a rapid motion of rotation as to derange its intended line of direction. Now, the earth and moon, and all the other planets belonging to the solár sys

tem, are in figure, oblate spheroids; and it has been demonstrated from facts deduced from physical and mathematical principles, by Sir I. Newton (be it remembered, however, that Mr. Mackintosh holds Newton's demonstrations at a discount of 99 per cent. since he invented his electrical theory !), but more fully by M'Laurin and Boscovich, and by hundreds of others, that bodies of such figures when in motion must revolve round their axes; and the greater the ratio of the equatorial diameter has to the revolving axis, so much quicker will the body revolve round its axis. Thus, of all the planets belonging to our system, the ratio of the equatorial diameter of Jupiter to its revolving axis is the greatest, being in the ratio of 14 to 13 nearly; and Jupiter revolves round his axis in a shorter time than any other of the planets, the time being only 9 hours and 56 minutes.

Mr. Mackintosh has sometimes put other puzzling questions to me. He wishes me to give a demonstration of what produced the first impulse, &c. I must inform Mr. Mackintosh that this proposition is far beyond the "ken" and

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scan" of my humble attainments. But if he will propose the question to his own pastor, and if he should happen to be of the orthodox way of thinking, there is no doubt but he will give him a true solution of it.

I shall take this opportunity of making a few remarks on the letter of your astronomical correspondent, Nautilus.—(See No. 697, p. 222.)

Nautilus states, "that he was rather surprised to read the elaborate refutation which Kinclaven, at p. 148, thought it necessary to give of O. N.'s most absurd conclusion, about the latitude of London and the pole star, &c."

Upon turning to p. 148, I find that my whole letter, which contains this elabo rate refutation, only takes up three-fourths of a single page; and the portion of it which I take in refuting O. N.'s article, takes up no less a space than eighteen lines! But Nautilus himself (notwithstanding my elaborate refutation) has given another refutation of the same article, still more elaborate, for he takes up no less than nineteeen lines. I am almost wicked enough to suppose, that Nautilus had made the above remark after trying the experiment with the bottle of crusted port,

but that before proceeding, he found it would be necessary to discuss the contents of the bottle. Again, adds Nautilus, “Kinclaven himself may be caught napping now and then; for instance, what does he mean by talking of the pole star's distance from the tropic of Cancer, &c. There is, certainly, an error here; "the tropic of," I should imagine, is a press error. But if Nautilus will again read over the elaborate article, he will find that in making use of these terms, I was only quoting O. N's statement, which he in his turn copied from Leadbetter's Astronomy. Well, Nautilus, to please you, I agree with you it is rather an improper expression-it ought to have been" the difference of longitude between the pole star, and the first scruple of Cancer."

I am, Mr. Editor, yours, &c.

KINCLAVEN.

SAFETY POWDER MAGAZINE-LIGHTING

CONDUCTORS.

Sir, In the year 1810, having witnessed the explosion of a powder magazine near Naples, and examined the effects upon surrounding objects, I bethought me of constructing one upon a principle that would obviate, or confine, as much as possible, the danger consequent to ignition. I communicated my plan to General Colletta, then Inspector General of Artillery, who so highly approved of it, as to order one on a small scale, to be constructed under my inspection. A circular pit was sunk twenty-five feet deep, and forty in diameter. The bottom and sides, after being lined with stiff clay, were built up with the best Puzzolana mortar and stone (or brick), and then coated with waterproof cement. The size of the cylindrical chamber, when finished, was twenty feet deep, and as many in diameter. Being protected from the rain, and allowed sufficient time to dry, a wood fire was kept up at the bottom, for several days, till the coating at last was perfectly dry to a considerable depth. A mixture of oil and lime was then plentifully applied, so as to fill up every little crack, and saturate the plaister and wall.

The superstructure for the door and roof above the surface of the ground, was made as slight as possible, as was also the roof. The object I had in view in this con

struction was, to confine the effects of an explosion to a vertical rise in the air; much more so, even, than in the springing of a mine; and, moreover, a part of my plan is, to give the pit, if the locality require it, an inclination from the perpendicular, of several degrees, so as to direct the possible explosion towards the point where the least damage would accrue. There are many ways of rendering such a magazine perfectly dry and water-tight, all too obvious for me to describe. As a means of abstracting from the confined air, a great portion of the water held in solution, I constructed several copper cylinders, drilled full of holes, which, being filled with lumps of fresh and well calcined lime, and suspended from several points of the roof at various altitudes, absorbed the moisture, if any existed. However well made, gunpowder is not near so deliquescent as is generally supposed; it only becomes so when made with impure nitre, and too large a portion of charcoal.

A magazine of only the above dimensions will contain conveniently, above one thousand barrels of gunpowder; and any number of such constructions may be clustered into one common enclosure in any eligible situation. I am decidedly in favour of lightning conductors, for the preservation of every kind of buildings and ships from the injurious effects of electric discharges. I have seen abundant instances of their saving qualities. But the most secure way of applying them in such a case as the present, is to have them isolated near, but not upon, the magazines. For such conductors to be of sure avail, they must be of a competent diameter, a mass of metal: those generally used are not a quarter big enough. The smallest part should be an inch diameter; and be it borne in mind, that a tube has twice the conducting power of a solid bar. Copper or zinc is far better than iron, in as much as they are less liable to oxydation. The upper extremities should be strongly gilt, or rather plated with gold or platinum. I say "extremities," because it is very advantageous for it to terminate in several branching points. If to preserve a metallic conductor from rust, it be coated with paint, or pitch, or tar, its saving qualities are not merely impaired, but it invites the danger it was meant to parry. The electric discharge