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118. The Nautilus Diving Apparatus; Exhibited by the Nautilus Company, 34, Great George-street, Westminster.

This machine consists of a working chamber, capable of accommodating a large or small number of divers, and surrounded by other chambers, in which the relative proportions of air and water may be so regulated, that the divers within the machine are able to sink or raise it, or to endue it with a buoyant power for lifting weights, according to circumstances. Compressed air is supplied to the apparatus through a flexible tube connected with a reservoir at the surface. For detailed description, see Journal of the Society of Arts, No. 224, page 244.

119. Apparatus for Improving the Ventilation of Mines, by Removing Noxious Gases from Fast-End Workings; James Wadsworth, Hazel-grove, Stockport, Cheshire.

The great difficulty in the ventilation of mines is the dislodgement of inflammable gas from those remote parts of the workings, through which it is found impracticable to introduce an atmospheric current sufficiently powerful to prevent the accumulation of such gas in dangerous quantities. Two means of effecting this object are here shown. The first consists of a double-acting bellows, mounted upon a carriage, running upon the ordinary tram rails. This carriage also carries a supply of socketpipes. When the machine is in use the pipes form communications between the inlet-nozzle

of the bellows and the deposit of gas on the one hand, and between the discharge-nozzle and the nearest level or air-course on the other hand. The bellows being then worked, draw in the gas through the inlet-pipe and expel it through the discharge-pipe into the level, where it mingles, and is carried off with the atmospheric current maintained by the ordinary means of general ventilation. The second apparatus causes a continuous current to be maintained through pipes from the highest part of the tast-end workings, where the gas accumulates, to the air-course, by means of rarefaction produced by heat. It consists of an inner or furnace-chamber, heated by the flame of a lamp, or partly by the flame of a lamp and partly by the combustion of a portion of the inflammable air. The lamp is contained in the box which forms the bottom of the furnace-chamber, the air to support combustion being admitted through valves guarded by tissues of wire gauze. There is a third valve for the admission of inflammable gas, if desired. The lamp is furnished with a wire gauze. A second chamber, of larger dimensions, envelops the furnace-chamber, having pipes of communication with the far end of the fast-end working on the one hand, and with the aircourse with the other. The heat radiated from the external surface of the inner or furnacechamber raises the temperature of the atmosphere in the space between the shells of the two chambers. The consequent exhaustion of the inlet-pipe causes a continuous in-draught of the foul air, which passes through the outer or larger chamber, and issues from the dischargepipe into the air-course.

119A. Patent Tin-Plate Cutting Machine, and
Patent Paper and Cardboard Cutting
Machine; Stephen P. Ruggles, Boston,
U.S. Exhibited by A. W. Conner, Duke-
street, Adelphi.

The peculiar action of these machines consists
in a rotary steel disc attached to gearing and
travelling through their whole length above a
`horizontal steel cutter fixed to the lower fram-
ing. This framing supports the table and butt
gauge. The box sliding along the upper portion
of the machine, carries the steel disc and gear-
ing, and in the handle there is a spring set up
by screws at the end, to keep the cutters up
to their work. In the smaller machine the
drawing action of the circular cutter necessary
to cut clean, and which in the larger is pro-
duced by gearing, is obtained by a piece of
cat-gut passed over the brass disc in the manner 145.
of a bow drill. These machines combine
the action of ordinary scissors with this ad-
vantage, that the cutting angle is always the
same, and the drawing action of a knife is
caused by making the disc rotate quicker than
it traverses along. This is of great utility in the
machines for cutting the thicker class of plates,
the plates being separated by the cutters enter-
ing barely ths of an inch, and so cutting with
much less power and avoiding curling and burr
on the edges cut. When circles are to be cut,
a carrier is hung from the traversing box,
pressing down the tin or other substance be-
tween the two discs by means of a cam-headed
lever above, and as the bearing centre travels with
the cutter, the same in feeding itself causes the
sheet to turn round and cuts a circle without
any previous centre-punching or scribing.
Ellipses, &c., may also be produced. In the
larger machines the top and bottom frames are
adjusted to each other by crank or eccentric
bolts at the ends so as to be set to cut different
thicknesses of plate, whilst the circular cutting
apparatus is detached from the traversing box,
but travels in the same direction and at the
same speed, thereby producing a similar result.

144. Magneto Electric Step by Step Telegraph; Siemens and Halske. Exhibited by C. W. Siemens, John-street, Adelphi.

This instrument possesses the advantages of great simplicity, entire suppression of the battery, and capability of working through a great length of line-wire (having been worked through 3000 miles) without intermediate relays. It is intended chiefly for railway companies, and private telegraphs, requiring only one line and being always ready for work. The instrument called the Indicator consists of two permanent magnets fixed to a frame, with the opposite poles turned towards each other, between which, are placed the moveable poles of an Electro Magnet. Positive and negative currents passing in succession through the coils of the electro magnet, cause a reciprocating motion of these poles, which are therefore successively attracted by the two permanent magnets. By this motion, a needle is turned on a dial step by step, showing the different letters and signs. The electric current is produced through a second apparatus called an Indicator, which consists of several permanent steel magnets, having one common anchor made of a soft iron core, covered with insulated copper-wire, and fixed so as to revolve in two bearings. This anchor is turned

145A.

145B.

by means of a wheel and pinion through the crank fixed over a dial, showing the letters and signs corresponding with the Indicator described above. By each half-revolution of the anchor, a current is produced alternately negative and positive, which passes through the coils of the Indicator, moving the needle as mentioned above. The first operation is to draw out the brass button on the side of the case at both stations, then by turning the handle one whole revolution on either station, it will give a signal on a bell attached to the Indicator. After the signals are received, the small ivory button below the dial of the Indicator is pressed inwards, and at the same time the handle turned until both the needle of the Indicator and the handle are on the blank field of the dials, when the instruments are in order for giving or receiving dispatches.

Portion of the Original Submarine Telegraph Cable laid down between Dover and Calais; Exhibited by T. R. Crampton, C.E., Buckingham-street, Adelphi.

This cable was taken up by Mr. Crampton during the repairs in January last, after having been submerged more than five years. It will be seen upon inspection that for all practical purposes it is equal to new, the gutta-percha being perfectly sound. This is a piece of the identical cable that first established the prac ticability of submarine telegraphs.

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In this invention the improvement consists in a novel mode of constructing the frame of castiron. The shape of the framing must of course depend upon the particular description of ininstrument to which it is to be applied, and the particular section of the iron framing must also in a great measure depend upon the same circumstances, and may be varied; but in practice, the T-shaped bar has been found to answer the purpose, and therefore it is preferred to use this form. For the purpose of receiving the pins on which the strings are secured, a piece of hard wood is employed, which must be let into the frame, and fastened

by bolts or screws. The surface of this piece of wood may be covered with a plate of soft metal, such as zinc or tin, so as to enable the bolts to hold the wood more securely. The sounding-board and bridge should be made of wood, and secured to the cast metal frame. Fig. 1 is a front view of one of the improved cast-iron framings; and fig. 2 is a sectional view, taken in the line H, G, of fig. 1. In this instance the strain of the strings is counteracted both in the head-beam and by the central longitudinal bar, J. A flange, b, is employed to support the piece of wood which receives the pins of the strings. Several forms

piece; and although cast-iron has been named as the material to be employed in making the metal frame, other metals or alloys of metals may be used with advantage for the best class of instruments.

158A.Specimens illustrative of a new process of coating cast iron and other metals with copper, &c.; L. Oudry, 2, Dunster. court, Mincing-lane.

189c.

189D.

of framing may be adopted for different kinds 215.

of instruments, the illustration showing one of the forms used. The several parts of these metal frames are cast together, and form one

The peculiarity of this process consists in the employment of an intermediate layer, of a gummy, resinous, or other substance, between the surface of the metal to be protected by plating and the electro deposit.

Aquarium. Exhibited by Philip Palmer, 118, St. Martin's-lane.

Improved Reflectors; U. Scott, 155, Grove-street, Camden-town.

These reflectors are made of sheet iron, and the surface is enamelled with glass or china.

Embroidery, executed by Machinery. Exhibited by P. de Fontainemoreau, 4, South-street, Finsbury.

[N.B.-These four pages should be taken out and bound with the Catalogue.]

curiosity, I examined what it contained. There were several pounds of fat pork, a large quantity of salt and fresh fish, remnants of all kinds of cold meat, scraps of bread and pie crust, two or three dozen plantains, and at least a couple of dozen of monstrous land crabs. Not black crabs, which in Jamaica are considered such dainties, but those horrid ghouls which feed and fatten in gravehim what he was going to do with that abominable mess, which he was stirring about most vigorously with the end of a paddle. He said "Me eat um massa for my break-faast." "What all that?" I said. "Hi! dat no much, me eat two time tree time dat for dinnaar." And this voracious brute was a thin, meagre looking creature, like the starved apothecary in Romeo and Juliet.

ponds in that island the grass becomes greatly impregnated with saline particles, and the sheep which feed upon it thrive much better than those which are depastured in other parts of the country. The flesh, from the saline quality of the food which they eat, becomes firm and juicy, and the fat in its richness approaches very much to that of venison. The sheep which are fed in the Jamaica mountains, although there are there ex-yards, and cheat the worm of its lawful prey. I asked cellent pastures, are very much inferior. The Indians in Guiana, and also in Central America, use very little salt with their food. Prescott, speaking of the Tlascalans, says, "for more than half a century they had neither cotton, nor cacao, nor salt. Indeed, their taste had been so far affected by long abstinence from these articles, that it required the lapse of several generations after the conquest to reconcile them to the use of salt at their meals." On the Belize river, about twenty miles from the Robinson Crusoe's man Friday at first refused to eat town of that name, there lives a man, or did a few salt to his meat, and it was a long time before he be- months ago, whose name is Jones by descent, and came fully reconciled to it. But Robinson Crusoe is a Richard by purchase. His longitudinal dimension enfiction. In one sense it is so-but there is more truth in titles him to be ranked amongst the sons of Anak, for that fiction than there is in many books professing to be the crown of his head is at least six feet and a-half authentic history. De Foe, the best and truest English above the level of the sea. His general appearanceprose writer we ever had, knew very well what he was spare, wiry, and springy, reminds one of Cooper's about when he stated Friday's repugnance to salt. He "Leatherstocking," and when he walks, "long and knew most of the voyagers of his day, and doubtless slouching is his gait," like Peter Bell the potter. He he derived from them the knowledge of the manners and has a massive head, covered with short, crisp, grey customs of different countries which he exhibits in his hair, a long aquiline nose, hollow cheeks, and a pair works. Salt is supposed to be a vermifuge, and I have of enormous jaws, which open and shut like an engine, read somewhere that there was formerly a law in a par-devised by some benevolent individual for the capture ticular locality in Germany, which condemned persons of unwary trespassers. This man possesses a most miwho had been convicted of certain crimes to eat their food, for the remainder of their lives, without salt, and that the consequence of this privation was-that they were destroyed by worms. I strongly suspect, however, that this is a fable.

As to the different effects produced upon the human constitution by nitrogenous, or plastic food, and carboniferous, or respiratory food, and the capacity of resisting the invasions of disease which the former gives, whilst the latter leaves the system a prey to the slightest attack, there was a remarkable instance in Belize a few years ago, when the cholera visited that town. The European inhabitants, and those black and coloured people who lived on nourishing animal food, nearly all escaped, whilst the Indians, and Spaniards whose food consisted principally of vegetables, dropped to the ground one after another, as if they had been shot.

Dr. Letheby speaks of the gluttony of the Hottentots, and the large amount of food which the inhabitants of Southern Africa generally are capable of consuming. I had once an African servant who would have been a match for any Hottentot that ever lived. He was the scion of a Royal family which had fallen into trouble. An exile from the kingdom of his Royal father, he did not disdain to earn an honest livelihood by communicating to boots and shoes the blackness and polish of his shining ebon face, and conveying to knives and forks the dazzling lustre of his dark eye. He was called Prince Pindar, the former name having been conferred upon him, no doubt, in reference to his exalted birth,-the cause of the latter I am ignorant of, unless it was his musical propensities, for he had a habit of constantly leaving off his work, putting both hands to his face, and entertaining himself with a low, confidential, melodious whistle. Be that as it may

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raculous twist, and would have eaten spoonful for spoonful with that famous Welsh giant (from whom, perhaps, he is descended) whom John the Giant Queller, as Fielding calls him, tricked so cleverly in the matter of the hasty pudding. Report attaches some romance to the history of Mr. Jones. It is said that in his youth he met with a disappointment. He had cast an eye of tender regard upon a black but comely daughter of Ham. But the "course of true love never did run smooth," and an "oyster," we are told, "may be crossed in love." The dark fair one scorned the alliance, and declined to become his "Sweet Jenny Jones." Upon this Poor Richard" took to his bow and his spear and has ever since been a great hunter before the Lord. But, though his heart was seared, he did not think it necessary to neglect one of the first injunctions to man; on the contrary, thinking with Benedict "that the world must be peopled," he became the father of a patriarchal progeny. Full seventy winters have now passed over his head and yet he is as active as ever, and

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"When the hounds are in the cry,
And the deer sweeps by,"

he sallies forth with his long gun, and his longer legs, in
search of savoury meat such as his soul loveth, for the ap-
petite of this worthy man is not the least impaired, but is
still as sharp and as keen as the north wind which whistles
on Ben Lomond. I have heard of a gourmand, who, on
seeing a hungry man make a hearty meal off a leg of
mutton, expressed his astonishment and disgust that any
person should waste so splendid an appetite upon such
food. I have known Mr. Jones polish off, in the hand-
somest style, a whole shoulder of mutton,—just to wile
away the time, until something more plentiful and sub-
stantial could be prepared for him. He will eat six
pounds of vension steaks, and a score of plantains, as we
would eat half-a-dozen oysters, to give him an appetite.
When he kills a deer, he sells one leg of it, breakfasts
off the other, and dines off the balance. A fearful man
Mr. Jones would be to encounter in a lonely place
on his return from an unsuccessful forage. The sight
of his long, sharp, white teeth, glittering like a row of
Turkish scimitars, and the opening and shutting of his
mighty jaws, which come together with a click, like "the
old oak chest which shut with a spring," would make
one's flesh creep, and one's blood curdle. It would be

worth while, for the sake of science, to negotiate for the purchase of his cranium, with the appurtenances, after his decease. I have no doubt that for a valuable consideration he might be induced to give a post obit. How far such an instrument would bind the executors and administrators, I am not prepared to say-for the head, being personal property, would, I presume, vest in them. I am, &c., R. TEMPLE.

SUBMARINE OPERATIONS. SIR,-In the Journal of your Society, of the 6th ult., I observe that Mr. John Bethell, in an address to the members at the meeting of the 4th idem, in speaking of diving dresses, stated that "he ought to mention that his diving dresses had been employed in the Bay of Navarino, in recovering guns from the Turkish ships, at a depth of 500 feet, which had been effected without difficulty, and with perfect safety to the diver." An announcement that diving could be carried on at a depth of 500 feet, was of so startling a nature, and, as I believed, so very far beyond any result attained in practice, that I have thought it right to look into the subject, and to collect some facts that might throw light upon it, and the conclusion at which I have arrived upon the evidence now before me is, that Mr. Bethell must have been misinformed as to the depth to which the divers descended in the waters of the Bay of Navarino.

I should not have troubled you with this communication had I not felt that the statement is calculated to mislead those who contemplate operations in deep water. If, indeed, works can be conducted at a depth of 500 feet, without difficulty, and with perfect safety to the divers," many works, especially those connected with mining operations, could be effected at an enormous saving of expense, as compared with the means now in general use.

That Mr. Bethell must be in error is, in the first place, I think, proved by the fact that there is in the Bay of Navarino no greater depth than 37 fathoms, or 222 feet, and I have ascertained, by reference to the Admiralty, that the Turkish ships referred to by Mr. Bethell were sunk in 18 fathoms, or 108 feet water; and, in the second place, that the pipes used for conveying the air to the divers were made of "many folds of cloth and caoutchouc." Now, if air at a temperature of 60 deg. Faht., be compressed in a pump, so as to resist the pressure due to a column of 500 feet of water, it would, in consequence of its diminished capacity for caloric, be raised to about 340 deg. Faht., and, as caoutchouc melts at about 250 deg. Faht., it is manifest that such a depth could not be attained by pipes composed of the materials described.

I have been occupied for some years in carrying on works in deep water, and have found much difficulty in any depth exceeding 60 feet, and I am unable to find any case on record in which a man has been more than 140 feet under water (and even this I very much doubt), and on this occasion it is said to have been found impossible for him to remain even the few minutes which were necessary for effecting the object desired.

of their limbs. This lasts sometimes for an hour, sometimes for three or four days. This breaks up the gangs in a most inconvenient manner. I am inclined to think that the smallness of the air-locks causes a too sudden transition from a great pressure to a much lower one. The men working in the bell suffer very much from the heat; indeed, when the pressure exceeds that due to 50 feet of water, the heat of the compressed air is sufficient to partially melt the india-rubber pipes, and to burn the leathers of the pumps, although they were in water."

Mr. Brunel, who has sunk the large cylinder forming the foundation for the pier at Saltash-bridge, to a depth of 83 feet, let his men work but three hours at a time, and yet found them seriously affected with rheumatism and congestion of the brain, so that one of them died upon the spot.

In putting in the foundations of the two new bridges at Rochester, at a depth of 62 feet, our assistants encountered many similar difficulties, arising from the pressure even at that depth.

To my mind it appears very necessary to advise the greatest caution in trying to execute works at the depth of even 100 feet, and is it not possible that when Mr. Bethell's friends, the "Greek merchants," from whom he says he got his information as to the divers in the Bay of Navarino, gave the depth to which they descended as 500 feet, they may have made a mistake in the first figure, and that the real depth was 100 feet and not 500 ?

I subjoin copies of some correspondence with Mr. Bethell on this subject, and I am, &c.,

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8, Parliament-street, Westminster, March 25th, 1857. MY DEAR SIR CHARLES,-I should have answered your note before, but I was at Birmingham till yesterday.

The deep diving I alluded to was in the Bay of Navarino, on the wrecks of the Turkish fleet sunk there, but as I got my information from the Greek merchants who sent out the apparatus, I cannot warrant the depth so great as stated.

But if the air pipes and pumps are strong enough, I should not be afraid of working in that depth. If the man is kept fully supplied with air of the same density as the water that surrounds his body he would be quite safe. Yours faithfully J. BETHELL.

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Spring Gardens, March 28th, 1857. The following extract from a letter dated April 19th, 1856, from my assistant, Mr. J. Folliott Stokes, who and must apologise for again troubling you; but the subject DEAR SIR,-I am obliged by your note of the 25th instant, superintended the construction of the bridge which car-is one of so much importance that I shall feel much obliged by ries the Paris and Lyons Railway over the Saone, in the your establishing the fact mentioned by you at the Society of City of Lyons, will be found interesting, as bearing upon Arts, on the 4th instant, and which is reported in the Journal this subject. This bridge is of wrought-iron, with two of that Society on the 6th instant, in these words :-" He (Mr. openings of 200 feet each, and consequently having one Bethell) ought to mention that his diving dresses had been empier, the foundations of which are composed of cast-iron ployed in the Bay of Navarino, in recovering guns from the cylinders sunk under pressure to a depth of 59 feet below Turkish ships, at a depth of 500 feet, which had been effected water, and you will observe that at this comparatively without difficulty and with perfect safety to the diver." small depth very serious inconvenience was experienced of, or any case I can find on record, that I naturally feel much The depth of 500 feet is so far beyond anything I have heard by the workmen, and the india-rubber pipes and leathers interest in obtaining all the facts. of the pumps were sources of constant delays and difficulties.

"The men find that on coming out of the apparatus under a pressure of 1 atmospheres, they lose the use

Of what material would you construct the pipes for convey" ing air to such a depth ?-Yours, faithfully, C. FOX.

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