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the top of the lantern, which was made tight in a pneumatic rim containing a little oil; the upper and lower apertures in the chimney were about { of an inch : the lamp, which was fed with oil, gave a steady flame of about an inch high, and half an inch in diameter. When the lantern was slowly moved, the lamp continued to burn, but more feebly; and when it was rapidly moved, it went out. To obviate this circumstance, I surrounded the bottom of the lantern with a perforated rim; and this arrangement perfectly answered the end proposed.

I had another chimney fitted to this lantern, furnished with a number of safety tin-plate tubes of the sixth of an inch in diameter and two inches long; but they diminished considerably the size of the flame, and rendered it more liable to go out by motion; and the following experiments appear to show, that if the diameter of the upper orifice of the chimney be not very large, it is scarcely possible that any explosion produced by the flame can reach it.

I threw into the safe-lantern with the common chimney, a mixture of 15 parts of air and one of fire-damp; the flame was immediately greatly enlarged, and the flame of the wick seemed to be lost in the larger flame of the firedamp. I placed a lighted taper above the orifice of the chimney: it was immediately extinguished, but without the slightest previous increase of its flame, and even the wick instantly lost its fire by being plunged into the chimney.

I introduced a lighted taper into a close vessel containing 15 parts

of air and one of gas from the distillation of coal, suffered it to burn out in the vessel, and then analysed the gas. After the carbonic acid was separated, it appeared by the test of nitrous gas to contain nearly of its original quantity of oxygen; but detonation with a mixture of equal parts of hydrogen and oxygen proved that it contained no sensible quantity of carburetted hydrogen gas.

It is evident, then, that when in the safe-lantern the air gradually becomes contaminated with fire-damp, this fire-damp will be consumed in the body of the lantern; and that the air passing through the chimney cannot contain any inflammable mixture.

I made a direct experiment on this point. I gradually threw an explosive mixture of fire-damp and air into the safe-lantern from a bladder furnished with a tube which opened by a large aperture above the flame; the flame be came enlarged, and by a rapid jet of gas I produced an explosion in the body of the lantern; there was not even a current of air through the safety tubes at the moment, and the flame did not appear to reach above the lower aperture of the chimney; and the explosion merely threw out from it a gust of foul air.

The second safety-lantern that I have had made is upon the same principle as the first, except that instead of tubes, safety canals are used, which consist of close concentric hollow metallic cylinders of different diameters, and placed together so as to form circular canals of the diameter of from

of an inch, and an inch and

to

long,

long, by which air is admitted in much larger quantities than by the small tubes. In this arrangement there is so free a circulation of air, that the chimney likewise may be furnished with safety canals.

I have had lamps made for this kind of lantern which stand on the outside, and which may be supplied with oil and cotton with out any necessity of opening the lantern; and in this case the chimney is soldered to the top, and the lamp is screwed into the bottom, and the wick rises above the air canals.

I have likewise had glass lamps with a single wick, and Argand lamps made on the same principle, the chimney being of glass covered with a metallic top containing the safety canals, and the air entering close to the flame through the circular canals.

The third kind of safe lamp or lantern, and which is by far the most simple, is a close lamp or lantern into which the air is admitted, and from which it passes, through apertures covered with brass wire gauze of of an inch in thickness, the apertures of which should not be more than

of an inch; this stops explosions as well as long tubes or canals, and yet admits of a free draught of air.

Having succeeded in the construction of safe-lanterns and lamps equally portable with common lanterns and lamps, which afforded sufficient light, and which bore motion perfectly well, I submitted them individually to practical tests, by throwing into them explosive atmospheres of firedamp and air. By the natural action of the flame drawing air through

the air canals, from the explosive atmosphere, the light was uniformly extinguished; and when an explosive mixture was forcibly pressed into the body of the lamp, the explosion was always stopped by the safety apertures, which may be said figuratively to act as a sort of chemical fire sieves in separating flame from air.

When the fire-damp is so mixed with the external atmosphere as to render it explosive, the light in the safe-lantern or lamp will be extinguished, and warning will be given to the miners to withdraw from, and to ventilate that part of the mine.

If it be necessary to be in a part of the mine where the fire-damp is explosive, for the purpose of clearing the workings, taking away pillars of coal, or other objects, the workmen may be lighted by a fire made of charcoal, which burns without flame, or by the steel-mill, though this does not afford such entire security from danger as the charcoal fire.

It is probable, that when explosions occur from the sparks from the steel-mill, the mixture of the fire-damp is in the proportion required to consume all the oxygen of the air, for it is only in about this proportion that explosive mixtures can be fired by electrical sparks from a common machine.

As the wick may be moved without communication between the air in the safe-lantern or lamp and the atmosphere, there is no danger in trimming or feeding them; but they should be lighted in a part of the mine where there is no fire-damp, and by a person charged with the care of the lights; and by these inventions, used with

such

such simple precautions, there is every reason to believe a number of lives will be saved, and much misery prevented. Where candles are employed in the open air in the mines, life is extinguished by the explosion; with the safe-lantern or safe-lamp, the light is only put out, and no other inconvenience will occur.

ON STEAM-BOATS UPON THE CLYDE.

been gradually increased in tonnage as well as in the power of their engines; and still larger boats and more powerful engines are now constructing: among others, one of about 100 feet keel and 17 feet beam with an engine of 24 horses' power; and one of equal burthen, having an engine of 30 horses' power. These boats are all neatly fitted up, and some of them even elegantly decorated. On board all the passage steam

By Robertson Buchanan, Esq. of boats are newspapers, pamphlets,

Glasgow.

(From Mr.Tilloch's Philosophical Magazine.)

So early as the year 1801, a vessel propelled by steam was tried on the Forth and Clyde inland navigation, but was laid aside, among other reasons, on account of the injury it threatened the banks of the canal by the agitation of the water and as far as I can learn, the same objection still subsists to the use of steam-boats on artificial canals so narrow as those usual in Great Britain. That objection, however, I should think, does not apply to some of those of Holland and other countries on the continent.

The first attempt on any scale worthy of notice, to navigate by steam on the river Clyde, was in the year 1812. A passage boat of about 40 feet keel and 10 feet beam, having a steam-engine of only three horses' power, began to ply on the river. Since that period the number of boats has gradually increased.

Besides three vessels which have left the Clyde, there are six at present plying on the river, two of which carry goods as well as passengers. They have on the whole

books, &c. for the amusement of the passengers, and such refreshments as are desirable on so short a voyage, a distance of about 26 miles by water, and 24 by land.

The voyage betwixt Glasgow and Greenock, including stoppages at intermediate places, is commonly accomplished in from three to four hours, the vessels taking advantage of the tide as far as circumstances will permit: but as they start at different hours from the same place, they are sometimes obliged to go part or nearly the whole of their voyage against the tide.

The voyage has been accomplished in 24 hours; the tide being favourable, but against a moderate breeze of contrary wind.

At first, owing to the novelty and apparent danger of the conveyance, the number of passengers was so very small that the only steam-boat then on the river could hardly clear her expenses: but the degree of success which attended that attempt soon commanded public confidence. The number of passengers which now go in those boats may seem incredible to those who have not witnessed it. Travelling by land has

not

not only been nearly superseded, but the communication very greatly increased, owing to the cheapness and facility of the conveyance. Many days, in fine weather, from 500 to 600 have gone from Glasgow to Port-Glasgow and Greenock, and returned in the same day. One of the boats alone has been known to carry 247 at one time. The increase of travelling in consequence of navigation by steam, may be estimated by the number that went in the common passage-boats before the introduction of this agent: at that time, the highest estimate even for summer did not much exceed 50 up and 50 down, and those generally of the lower class of the people. The number that then went by coaches may be thus estimated four coaches up and four down, which might average six passengers each.

adopted by trunk-makers, bookbinders, and others, who use great quantities of paste, it would produce a very material saving of flour, which in years of scarcity might be of the greatest consequence. The following formula used in China was lately communicated to the Right Hon. Sir Joseph Banks, Bart. by a gentleman at present in Canton.-Mix together bullock's blood and quick lime, in the proportion of one pound of the latter to 10lbs. of the former. It becomes a stiff jelly, in which state it is sold to the consumers, who beat it down with an addition of water into a state sufficiently fluid for use. At Canton it will keep five or six days in the hot weather and ten or twenty days in the cold. In Britain it would probably keep longer.

HEMP AND FLAX.

In the summer, the pleasure of NEW MODE OF MANUFACTURING the voyage and the beauty of the scenery attract multitudes; and the bathing-places below Greenock have, in consequence of the easy passage, been crowded beyond former example.

The scenery near Glasgow is sylvan and beautiful, but becomes bolder and more picturesque as the river descends, until it terminates in the rugged mountains of the west Highlands.

CHINESE PASTE.

(From Dr. Thomson's Annals of) Philosophy.

The method of making paste in China is much more economical than the mode followed in this country. Were it universally

(From the Same.)

About two years ago Mr. Lee took out a patent for obtaining hemp and flax directly from the plants by a new method. He has established a manufactory for the purpose at Old Bow, on the river Lea, near London, where his method, and the result of it may be seen. I consider Mr. Lee's invention as the greatest improvement ever introduced into the linen business, and as likely to occasion a total change in the whole of our bleach-fields. Hitherto the only way of obtaining hemp and flax has been to steep the plants in water till they begin to rot. They are then exposed for

some

some days to the sun spread out upon the grass, after which the woody part, now become very brittle, is removed by the flaxmill, the nature of which is too well known to require any description. By these processes the fibres of the flax are weakened, and a considerable portion of them is altogether destroyed and lost. The flax, too, acquires a greenish yellow colour, and it is well known that a very expensive and tedious bleaching process is necessary to render it white. Mr. Lee neither steeps his flax, nor spreads it on the grass. When the plant is ripe, it is pulled in the usual way. It is then thrashed, by placing it between two grooved wooden beams shod with iron. One of these is fixed; the other is suspended on hinges, and is made to impinge with some force on the fixed heam; the grooves in the one beam corresponding with flutes in the other. By a mechanical contrivance almost exactly similar, the woody matter is beaten off, and the fibres of flax left. By passing through hackles, varying progressively in fineness, the flax is very speedily dressed, and rendered proper for the use for which

it is intended. The advantages of this process are manifold. The expense of steeping and spreading is saved; a much greater produce of flax is obtained; it is much stronger; the fibres may be divided into much finer fibres, so as to obtain at once, and in any quantity, flax fine enough for the manufacture of lace. But the greatest advantage of all remains yet to be stated. Flax manufactured in this manner requires only to be washed in pure water in order to become white. The colouring matter is not chemically combined with the fibre, and therefore is removed at once by water. It is the steeping of the flax and hemp, which unites the colouring matter with the fibres, and renders the subsequent bleaching process necessary. Thus, by Mr. Lee's process, flax and hemp are obtained in much greater quantity, of much stronger quality, and much finer in the fibre than by the common method, and the necessity of bleaching is altogether superseded. The great importance of such an improvement must be at once obvious to every

one.

MISCELLANIES.

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