before the plunger, it is evident that the plunger is driven with atmosphere pressure at the rate that air rushes into a vacuum, barring the loss of velocity by friction. In all the atmospheric telegraphs heretofore proposed, the motion of a long column of air behind the ball or carriage has presented an insuperable obstacle to its operation on a long line. To obviate the evil of working on a long column of air behind the piston, new air is admitted at different stations along the line behind the plunger, and the long column is cut off so that the action is like a succession of short effectual efforts. This is done in an ingenious manner, by valves hanging in the main tube connected with the atmosphere, which are acted upon by the plunger as it rushes through the tube, when the air is cut off a short distance behind the plunger, and a new column commences to act, to force the carriage through. This propeling power is so great as to produce an apparently instantaneous motion of the plunger with its load from one end to the other of the model tube on exhibition, which is about 30 feet long and 1 1⁄2 inch in diameter; indeed the plunger issues forth with so much force, when not confined, as to knock down violently a heavy billet of wood placed opposite the end of the tube, if it is left open. The speed is estimated at about 1000 miles in an hour. The apparatus is so arranged that there can be intermediate stations upon the line, at which the progress of the plunger can be arrested, or, if preferred, it can pass directly through to the terminus. The inconvenience of the sudden shock occasioned by the arrival of the plunger at the end of its journey is avoided by an arrangement by which a portion of the air in front of it is compressed and allowed to escape, but gradually, forming a sort of cushion to ease the jolt.

For the purpose of carrying the above described invention into effect, it is proposed to build a line of atmospheric telegraph 2 feet in diameter, from Boston to New York, for the conveyance of letters and packages to and from the said cities and intermediate places, allowing fifteen minutes for each transit; sending from Boston to New York at every hour, and from New York to Boston at half-past every hour, twelve hours each day. The cost of laying it down is estimated at $2,000 per mile. There will be supply valves as often as once in 25 miles, and intermediate stations at suitable points; for instance, at Worcester, Springfield, &c. There will be air pumps at all the sta

tions.

SMOKE CONSUMING FURNACE.

The London Mining Journal describes and praises very highly a smokeless furnace, invented and patented by Mr. John Lee Stevens. The invention consists in the combination of two sets of fixed firebars, the first of which is chiefly fed by the scoria and cinders voided from the second or upper set of fire-bars, with a caloric plate, the face of which may be protected by a few fire-bricks; by which arrangement the current of air entering at the lower part of the furnace passes through two stratą, of fire, and thence between the caloric

plate and the bridge, and is thus so intensely heated as continuously to produce the entire combustion of the gaseous products of the fuel, and to prevent the ordinary formation of smoke.

Smokeless Chimneys.-Major Browne, of London, has recently patented an apparatus for preventing the egress of smoke from the tops of chimneys. The invention is applicable to old chimney shafts, or in the construction of new ones the height might be very considerably reduced. The top of the chimney is closed in, and at about half-way up in those of present construction an opening is made in the side as large as the structure will allow. Outside of this an iron box is firmly secured, in which is a foliated revolving cylinder, its axis placed horizontally, having a grooved pulley geared to the motive power by which it is set in motion. The leaves of this cylinder are curved downwards in the direction of its rotation, to facilitate collecting and carrying downwards the solid particles of carbon, and the denser vapors into a tank beneath, containing water, and in which it partially revolves. This tank has two openings, one to insert fresh water, the other to withdraw the collected matters. When the smoke reaches the opening it comes within the immediate action of the draught caused by the rapid revolution of the vanes, and is quickly condensed in the cold water trough.

A new law for the abolition of the smoke nuisance in London went into operation in August, 1853.

There are eight sections in the law, and it enacts that from and after the 1st of August, furnaces in the metropolis shall consume their own smoke, under penalties described. The act extends to any mill, factory, printing-house, dye-house, iron foundry, glass-house, distillery, brewhouse, sugar refinery, bakehouse, gasworks, waterworks, or other buildings used for the purpose of trade or manufactures, within the metropolis. From the same day steam-vessels on the Thames above London bridge are to consume their own smoke, under penalties to be recovered in a summary manner before a magistrate. The words, consume or burn the smoke." are not to be held in all cases to mean, "to consume or burn all the smoke;" and the justice before whom any persons shall be summoned may remit the penalties if they are of opinion that such person has so constructed or altered his furnace as to consume or burn, as far as possible, all the smoke arising from it, and has carefully attended to the same, and consumed or burned the smoke arising from the furnace. Constables may be empowered to enter and inspect furnaces and steam engines.

66

IMPROVEMENTS IN CRUSHING AND PREPARING ORES.

Machine for Separating Ores.-An important apparatus for separating ores and other substances of different specific gravities and of different magnitudes into their constituent parts, has been invented by Victor Simon, of Nerviers, Belgium; the inventor, Mr. S., accomplishes the desired object, by passing a current of air through a long trunk or tube placed horizontally, or nearly so, with a series of re

cesses arranged in the bottom of the tube for the reception of the ores, or other substances; these substances, after being pulverized, are fed to one end of the tube from a hopper placed above it, and are subjected to the uniform current of air above the recesses; the heaviest particles fall immediately to the bottom of the tube to the receiver prepared for its reception, and those lighter to the adjoining recesses, and so on, in proportion to their specific gravities, the lightest being found in the receiver farthest from the feed opening. The particles of matter received in any one receiver of the series will have a specific gravity so much greater, compared with that of the other particles, as their volume is less, and vice versa. When thus classified, the perfect separation of the different substances may be easily affected, and, at the same time, the removal of any impurities which may exist in the pulverized material. This easy and simple classification and separation of particles of matter is a most desirable result, and will very much facilitate the analysis of ores and other substances submitted to its action. The improvement has been already tested in Belgium, and is believed to be one of utility.-Scientific American.

New Method of Crushing Ores.-A new method of crushing ore, invented by Capt. Sharpnell, of London, is thus described in the London Mechanics Magazine:

"The invention consists of a chamber about ten feet long, eight feet high, and six feet wide, the back of which is made of inch and a half wrought iron, and the sides of sheet iron. The sides are riveted and strengthened with ribs. The whole rests upon a bed of timber strongly framed. A short railroad track is placed in front of the box for the cannon to run upon. The gun is charged with powder, and a wad rammed down upon it, and all above the wad is charged with broken pieces of ore, and the whole covered with another wad. It is now moved forward upon the rails, against the front of the chamber, in which there is a circular hole, rather larger than the muzzle of the gun. The muzzle is just introduced within the thickness of the plate, the piece is primed and fired, when the charge is projected against the strong thick plate forming the back of the box. To relieve the sides of the box from the concussive force, the roof is formed in doors upon hinges, which suddenly fly up when the explosion takes place, and act as safety valves, after which they immediately fall. The reduced ore is acted upon by a gentle blast, which sends off the lighter particles, and allows the heavier metallic to fall. A preforated false bottom allows the reduced ore to fall into a drawer, which is withdrawn with the dust, to submit the latter to the winnowing process."

Gardiner's Quartz Crusher and Amalgamator. This invention consists, first, of a kettle or trough, which in the working machine is to be of cast iron, 8 feet long, and of sufficient width to admit a ball 3 feet in diameter. This trough is stationary, is set horizontally, and is firmly imbedded in a framework of wood. The ball which travels in this trough has a pole passing through its centre, serving as its axis or journals, to which is attached a horizontal shaft working on the journals of the ball; and that shaft is attached to a crank or to the piston

of the engine, which when set in motion gives the ball an oscillating motion, causing it to travel back and forth the entire length of the trough in which the quartz is placed, at the rate of about 600 feet per minute. At one end of the trough are small apertures or slats, through which the quartz, after being crushed to the size of large peas, is forced by the motion of the ball, falling into a stationary cast iron kettle or mortar of about 3 feet diameter. Into this kettle is inserted a tolerably close-fitting cast iron half-sphere, or perhaps more properly a pestle. By the operation of the machinery two motions, gyrating and rotary, are given to this pestle. As the crushed quartz passes from the trough into the mortar, it is (such is the theory of the inventor) pulverized to an impalpable powder, and passed out at the bottom into an amalgamator immediately beneath. The amalgamator consists of a cast or wrought iron cylinder of any given length and size, placed horizontally, with steam-tight heads at both ends, and resting on hollow journals cast on the heads, through which the pulverized quartz is received into and discharged from the amalgamating cylinder.

er.

Berden's Quartz Crusher and Amalgamator.-In this machine, the crusher is an iron ball or globe, weighing five thousand pounds, and some thirty inches in diameter, which revolves in a mammoth cup, not unlike a potash kettle, which is obliquely suspended from and strongly secured to a heavy wooden framework, which should be firmly imbedded in the earth or fastened to an unyielding platform resting thereon. This cup or basin is made to revolve by an ordinary application of steam-power by means of a belt, and thus the ball, continually seeking the lowest position, revolves without changing its place, being attached by a pin to a stem in the centre of the cup. A stream of water is conducted into the cup from above, and forms a pool of some three or four pailfuls around and under the ball. The mercury is of course under the ball, and the quartz is shoveled into the pan or may be poured in from a hopper above. So far, gold-miners will recognize it as an improved Chilian Mill, of extraordinary powBut beneath the pan or cup or rather in a cavity at the bottom thereof, formed expressly to this end, a small fire is made, which (being fed with air through half a dozen orifices at regular intervals surrounding it,) is fanned into lively action by the revolution of the cup, and heats the quicksilver moderately without heating essentially the water, continually pouring in above it, dashing about and running off, surcharged with the pulverized quartz. The effect of this contrivance is claimed to be the perfect amalgamation of the gold (or other precious metal) with the thus enlivened and expanded quicksilver without subliming that metal and causing it to pass off as vapor. By this means it is claimed that the very last particle of gold is extracted from the quartz and held by the mercury, ensuring a product per ton of quartz three or four times as great as has hitherto been secured; so that the owners of this machine may make money faster by washing the "tailings" or already pulverized and exhausted quartz at any gold-digging already worked, than can be obtained by other machines from rich quartz not previously exhausted.

COOKING BY GAS.

Some interesting experiments have recently been made in London, under the supervision of M. Soyer, to determine the question on the merits and economy of roasting by gas. The results of the first trial, which took place on the eighth inst., was, that 36 legs of mutton, weighing 288 lbs., were roasted at a cost of 1s. 2d. In order to arrive at more positive results in regard to its economy, a second trial was deemed requisite, which took place on the 11th inst., when equal weights of mutton were cooked-23 joints, weighing 184 lbs., were roasted by gas at a cost of 104d, with gas supplied at four shillings per thousand feet; when cooked, the above weight of meat was found to weigh 146 lbs.; dripping, 19 lbs.; of gravy or ozmazome, 2 lbs.,— thus showing the actual loss to be 83 lbs. Twenty-three joints of mutton, weighing 184 lbs., were cooked in the usual way, namely, in one of Count Rumford's ovens, hitherto considered the most economical way of roasting. When taken out they were found to weigh 132 lbs. ; dripping, 18 lbs.; gravy none; thus showing a loss of 34 lbs. The coke consumed by the oven weighing 102 lbs., coals 30 lbs., thus proving the great economy of gas over the oven by a saving of 13 lbs. of meat, 1 lb. of dripping, and 23 lbs. of gravy, the value of which saving is as follows: Meat, at 6d. per lb., 6s. 6d.; dripping, at 5d. per lb., 5d.; and gravy, at 1s. 6d. per lb., 4s. 14d., making a total of 11s. Od.

DUPLEX SAFETY REIN.

A striking and valuable improvement in bridle reins, was exhibited at the New York Crystal Palace, by W. A. Holwell, of Canada, designed either for riding or driving. He calls it the "Duplex Safety Rein." Ordinarily, there are two reins to every bridle, one of which connects with a curb, and the other with a snaffle. This improvement proposes to dispense with one of these altogether. A single leather rein is attached to the curb-bit. A short elastic connecting piece, or false rein, is attached at one end to the main rein, and at the other to the ring of the snaffle-bit. With this arrangement, so long as the horse moves gently, the driver or rider bears on the connecting piece only, and through it upon the snaffle-bit. If the horse is restive or hardmouthed, his resistance stretches the connecting piece until the pressure is thrown upon the main rein, and through it upon the curb or stiff bit, thus bringing its lever power into play. The moment the animal becomes tractable again, the elastic piece contracts and transfers the natural pressure of the horse's mouth to the snaffle bit, the lever bit becoming instantly relaxed. The material used by Mr. Holwell, for his model, is a gum-elastic tube with a metallic hook at one end, to attach it to the snaffle or cheek-ring, and a little button at the other, for whose reception holes are punched along the main rein. The advantages proposed by this promising though simple invention, are a more natural, self relying movement on the part of the horse,