must be had recourse to, either by the mouth of the operator, or by a pair of bellows. The patient's nostrils must be closed, while the operator blows with considerable force at once into the chest ; then press the chest as before directed, and so repeat the operations. If the lungs can be well inflated by these means, we must persevere for a considerable time; but if it fails to produce the necessary inflation, close the mouth and one nostril, while the operator blows forcibly into the other, to produce the wished-for effect. A small tube of wood, metal, or a tobacco pipe, if at hand, would be a very serviceable instrument for this purpose, but if not at hand, a moment must not be lost in accomplishing it. Insufflation by the breath of another, although not of so pure an air, yet it more than counterbalances this defect by its superior temperature. This inflation and expellation of air should be repeated about fifteen times in a minute. Whilst the insufflation is going on, frictions over various parts of the body, particularly the chest, must be conducted by others, and where electricity or galvanism can be had recourse to, some powerful shocks might now with advantage be passed through the heart and lungs. The nostrils might likewise be irritated with a feather dipped in hartshorn; and some warm, stimulating liquids, as spirits and water, be conveyed, by means of an elastic tube into the stomach, or by means of a glyster into the bowels, which frequently proves of great service. Bleeding should seldom be had recourse to; and it appears not to be warranted except the countenance be swollen, injected, or purplish, and the veins full and distinct, which is often the case after hanging, but seldom from immersion or suffocation. Bleeding may be of much greater benefit in the succeeding stages after we have restored animation.

"The foregoing remedies should be persisted in for some hours, and we should not be satisfied that life is extinct because our efforts are not speedily crowned with success; nothing should convince us of the futility of the means adopted, unless stiffness of the limbs and other indications of death present themselves.

"I now proceed to those short directions which I could wish to see placed in the hands of all sailors, miners, and inhabitants of seaports, in fact, universally distributed; it might then prove the happy means, under Divine Providence, of rescuing more than one unfortunate fellow creature from a premature death.

Drowning.

"Suppose we witness the upsetting of a boat or other accident, whereby one or more are submerged:-Instantly dispatch a messenger for medical aid, while we ourselves hasten to the spot;remove as quickly as possible all the wet clothes from the body, and supply their place by some of our own;-raise the head and shoulders, while you convey it to the nearest warmth and shelter, and while warm blankets, beds, &c., are in progress, simulate the act of respiration, by first inflating the lungs by blowing strongly with your own mouth through the mouth or nostrils of the patient;

then as quickly press both sides of the chest with your hands, and so on alternately about fifteen times in a minute; and when this has been repeated a few times, let others rub different parts of the body with warm hands, or flannels smeared with butter or oil, while the process of inflation, &c., is still persevered with. Let no salt or spirits be rubbed over the body, as the cold thereby produced is prejudicial.

"The body may be placed before a good fire, or in a warm bath of the temperature of about 100°, or it may be placed in bed between warm blankets or two warm persons, while you persevere in the above mode of imitating natural respiration, until the arrival of superior aid; the restoration of the circulation, and in all probability the life of your friend or neighbour, mainly depends on your early and correct performance of this operation.

Hanging.

"In cases of hanging, as in all other accidents, dispatch a messenger for a medical man, and direct your first efforts towards the stricture on the windpipe caused by the cord; then proceed, as directed in cases of drowning, to inflate the lungs by blowing forcibly into the mouth, press out the air which you have forced in, by your hands on either side of the chest, and so continue the operation. In case there should be a paleness of countenance, together with coldness of the body and limbs, you might use friction as before directed; but should the face be flushed, you had better defer the use of frictions until blood is removed from the jugular vein.

Noxious Gases.

"When suspended respiration arises from a person descending incautiously into an old well, mine, brewers' vat, or by sleeping on a lime kiln, or in a room with burning charcoal, &c., we immediately conclude it arises from the presence of carbonic acid. If in a confined pit, first dash a few bucketsful of water into the place, and direct some quicklime to be quenched as near the body as possible; if a candle will continue lighting near the body you may safely venture down for its removal, (and which should be as quickly performed as possible) to the pure air. Similar steps should be adopted in a mine where the suffocation appears to arise from gunpowder smoke. As soon as you reach the body, blow forcibly into his mouth with your own, taking care to close his nostrils, then press the chest as before directed, and continue to repeat it by every possible means. When brought into the pure air, similar means must be adopted as directed under the head of drowning; but we must remember that in every case of apparent death from these causes, our first efforts must be to inflate the lungs with the warmest and purest air possible, then expel it by pressing the chest with both of the hands, then inflate again, and again expel it, and so on. You had better continue this operation without interruption until the arrival of medical aid, than venture on any other mode, the operation of which you may not be fully competent to judge, and risk the

annihilation of a remaining spark of life, by an injudicious use of it."

7.—On a Mercury Safety Valve. By Mr. OCTAVIUS WILLIAMS. 8.-On a Self-regulating Feeding Apparatus, an Alarum and Water Indicator for Steam Boilers. By Mr. OCTAVIUS WILLIAMS. 9.-On a Method of Patching Steam Boilers, without lifting out all the water. By Mr. JOHN HOLMAN.

10.-Description of the Model of a Fishing Boat, fitted so as to prevent her sinking in the event of her filling with water. By Mr. J. HUSBANDS.

11.-Description of Mr. J. PHILLIPS's Tide Wheel.

12. On the Machinery used for raising Miners in the Hartz. By JOHN BASSET, Esq. M.P.

13.-Description and Account of a New Kind of Mariner's Compass. By W. SNOW HARRIS, Esq. F.R.S., &c. &c.

"The compass needle consists of a straight bar about 7 inches long, an inch wide, and of an inch thick; it is made of fine steel, well tempered and hardened throughout its whole length; it is placed edgeways, and is delicately balanced on a fine point, resting on a centre of agate. Instead of the ordinary compass card, a transparent circular disc of tale is attached to the bar, at its under edge, on which the different points, &c., are either painted in transparent colours, or otherwise laid on it, on very thin paper, so that the whole is quite transparent; and in order to ensure and regulate the horizontal position of the whole, at any time or place, there are two small sliders of brass underneath, and on each side of the centre, so contrived as to slide and turn with friction into any required direction by means of two slits in them and small stop

screws.

"The compass bar, with its talc circle beneath, is now placed centrally within a ring of hammered or rolled copper, the poles of the bar, which project a little beyond the card, being distant from the interior of the ring about th or 4th of an inch. This copper

ring is about 1 inch wide, and th thick; it is turned up and finished in a lathe, so as to be perfectly circular; the centre piece carrying the needle is supported on a cross bar attached to the ring, and the centre part accurately adjusted in the lathe.

"The whole is finally set within a glass bowl or other case, according as it is required to light the compass from beneath or above, and placed in gimbles in the usual way, the perfect transparency of the single disc of talc renders the compass card very visible and clear when lighted from beneath.

"The great steadiness of the compass under all sorts of motion is very remarkable. It has been successfully tried in a few ships of the navy, and is still on trial. The needle being placed on its edge, it is liable to little error in its magnetic line; it has, besides, great magnetic energy and great delicacy of suspension, and is unembarrassed by a heavy card whilst at the same time the

magneto-electrical induction on the copper ring effectually preserves its natural direction undisturbed-these are advantages of no ordinary kind.

"Mr. Harris has shewn (Transactions of the Royal Society for 1831), that when a magnetic bar oscillates freely within a series of concentric rings of copper, accurately and closely fitted one within the other, the restraining force of the copper with a given magnet is inversely as the squares of the distances from the pole of the bar, and directly as the quantity of copper within the sphere of its action, the matter being supposed to be condensed into an indefinitely thin ring, and taken at some intermediate or mean distance within the surface, where the sum of the forces may be supposed to produce the same effect as if exerted from every part of the mass, and that hence the energy is also directly as the density. He also found that with a given magnetic tension in the bar, the restraining force no longer increased sensibly after a certain number of rings; that in fact the number of rings requisite to exhaust as it were the magnetic force, varied in some ratio of the power of the magnet; thus, with the bar employed, no sensible increase of energy in the whole was observable, after the tenth ring, the effect being the same with ten as with any greater number of rings.

"In the application, therefore, of a copper ring to the purpose of restraining the oscillations of the compass at sea, it is desirable to have the poles of the bar as near as we can to the interior of the ring, to have the copper as dense as possible, and give it greater or less thickness, in proportion to the power of the compass bar. Much has been said, and many experiments tried, with a view of determining the best form for a compass needle; it will, however, probably be found, that the simple bar above described is, upon the whole, not only the most accurate, but in every respect the best. Its form greatly simplifies the workmanship necessary to its construction, and admits of the various other scientific processes upon which its action depends being easily and perfectly carried out. the steel be well chosen, and be properly tempered, such a bar is susceptible of a very high degree of magnetic energy, which it will be found to completely retain." Remarks.

If

We shall at all times be glad to hear of improvements in so valuable an instrument as the steering compass; but the operation of every novel principle, attempted to be introduced, ought to be clearly and minutely explained, and most scrupulously examined, before its adoption can be warranted and justified by science. In the present case, such inquiries as the following are of great importance, a direct and unequivocal answer to which being the only means of ascertaining whether the newly-introduced principle be an improvement, or otherwise, to the steering compass.

What are the respective routes of those electric currents which are produced by the needle's eastward, westward, and vertical motions?

What are the arrangements of the north and south magnetic forces of those currents respectively?

In what manner does each individual magnetic arrangement operate on the needle ?

As the Admiralty, and indeed every naval officer in the service, must be deeply interested in this subject, Mr. Harris can have no objections to giving them that satisfaction which they have a right to demand on the above-named particulars, which require full, clear, and immediate explanation.

Should steadiness be an essential qualification to constitute a good practical steering compass, that point would be easily attained by vanes of any light material attached at right angles to the under side of card.

14.-Meteorological Register, Map and Tables for Barometer, Thermometer, and Rain-guage, at various places.

15.-Remarks on Electro-Metalurgy. By Mr. T. B. JORDAN. "In the course of a limited series of experiments, which I have tried in this interesting branch of the useful application of electricity, a few ideas have occurred to me, which, I believe, possess the charm of novelty. As no suggestion, however trivial in itself, can be considered altogether unimportant, when it bears on the practical application of science to our manufacturing arts, I feel no hesitation in laying before the Society the following remarks, with a view to their being made public. It is quite evident that Mr. Spencer's recent discovery of the art of depositing metals from a solution of their salts by galvanic action, has placed in the hands of manufacturers a new means of copying, and the importance of this will be immediately apparent to those who know how large a portion of our manufactures in metal are the copies of original matrixes, or more indirectly the results of other copying processes. Some imagine that because it is only the means of copying, it is really of little value; but it is impossible to allow this to be a valid objection, when we consider how very few metal articles there are, which do not wholly or in part owe their origin to copying. If, then, it can be shewn that this method possesses advantages for some description of work, which are not common to any other, and that there is good reason to suppose it may be economically conducted, then we may fairly infer, that it will in due time become one of the ordinary processes of our factories.

"Its advantages are numerous, and some of them so self evident that they only require naming to be allowed; for instance, any surface, whatever be its material or form, may be formed with a coating of metal, without heat and without force; this coating may be allowed to accumulate to the required thickness, and may then be removed from its original, when the surfaces which were in contact will be found to be so perfectly alike, that it is impossible to discover the minutest scratch in one which has not its counterpart in the other. In proof of the accuracy of the copy, I