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ing the results together giving 2862-35, and sub- Vienna, a machine for needlework, by which, it is screw, combining with it the high velocity of fortracting therefrom 171-4, thence leaving 2690-95 said, every kind of sewing may be executed with ward motion to be obtained from the use of the for a remainder. This quantity, multiplied by the utmost precision. The Emperor of Austria fish-tail at the same time astern of the rudder. It one-twelfth of the distance between the horizontal has granted a pateat to the inventor. Should is well known that one defect of the screw is, that sections, and then by the constant number 2 x 4-2 these mechanical perfections make much farther it does not, under all circumstances, e.g., head to before mentioned, will give 2825-4975 cubic feet, advancement, every thing in the world will wind, utilize sufficiently the steam power which or 80-7285 tons for the displacement between these shortly be executed by machine,"

might be applied to it if there were more perfect lines; and, therefore, the displacement to the To Americans, however, the world is indebted resistance. This, any greater area brought to 2 W.L. is equal to 219-84 — 80-7285 or 139:1115 for the invention of sewing machines adapted to bear on the resisting medium, would effectually tons.

common use in tailoring, shirt-making, dress- absorb; but no advance with the screw alone, in To form the scale of displacement, a vertical making, boot-making, and similar trades. The this direction, is possible without at the amg line, as L.W.L., 5 W.L, drawn on page 298, is high prices paid for common hand-sewing in the time increasing the draught of water. I will taken as the axis of abscisse, and the dotted line United States naturally led to the invention and give a brief description of the mode of construcperpendicular to it, marked“ lower part of keel,” use of labour-saving machines adapted to plain tion and appliance of a “fish-tail” propeller, acas the other axis of co-ordinates. From the point sewing, just as the high prices of fancy articles for cording to this view. The propeller should first where these axes intersect the heights of the hori-clothing had previously led to the introduction of be framed with a central boss, and with hammered zontal sections, above the under side of the keel similar machines among the lace-makers and em- brass springs exactly like the bones of a fish's tail amidsbips, are set up according to scale; through broiderers of England. The American inventors projecting from it above and below. Then this the points 41 W.L., 4 W.L., &c., thus obtained, lines who are best known in the United States and in framework should be covered with india-rubber, are drawn parallel to the dotted line, and from the Europe, are Elias Howe, jun., and Sherburne c. to complete the imitation. The motion might bo vertical line distances are set off upon them, pro- Blodgett. The only American manufacturer who obtained from the end of the screw shaft by an portionate to the displacement in tons to

known

is J, M.

for past is of an inch to 10 tons; consequently, the dis- years occupied the first place ninong the inventors tance from the vertical line to the point in the of sewing machines. His patent of September 10, curve at L.W.L. is 21:984 feet on the “ quarter” 1816, for the combination of the needle and the scale. The distance on the horizontal line at shuttle has been generally acknowledged to be at 2 W.L. to the point in the curve is 13.91115 feet; the foundation of the sewing machine trade in the and so on for the others.

United States. All the leading manufacturers have The very small displacement below 5 W.L. has accepted licences from him, and his income from heen neglected in our calculations; consequently, the royalties thus received is said to amount to the curve must meet the vertical line at 5 W.L. not less £20,000 annually. Sherburne C. Blodgett

is the thus found, the displacement corre his

known in Great sponding to any water-line between 5 W.L. and was awarded at the Exhibition of 1851. In con. tion from the combined circu motion of the L.W.L. may be readily found. Thus:-- From the sequence of this exhibition of sewing machines in shaft, and this would admit ou ia joint which is dotted line set up a distance equal to the draught London in 1851, and of their exhibition subse- of course necessary being placut in the false stein of water on the proper scale; and through the quently in Dublin in the following year, the post or rudder, as most advisable. The rudder point found draw a level line cutting the curve American idea of sewing by machinery became would be cut through and jointed, as in the case 2. The distance of their intersection from the current and popular in this country. Very soon of those screws which now work astern of the vertical line when set off on the scale of tons will a demand was created for machines superior to rudder, and which are not uncommon. To provide give the displacement required.

those which had previously been used in embroi- for the cessation of motion in the fish-tail when

dering and stay-making, and improved inachines going astern, it would be necessary to give a cerTHE SEWING MACHINE.

were rapidly introduced, most of them, however, tain degree of “fore and aft” play to the eccenA SKETCH OF THE HISTORY OF ITS INVENTION. being of American invention and manufacture tric on the screw shaft, so that the back pull The essential parts of a sewing machine are but The demand for army clothing during the Crimean should disengage the 'eccentric from its frame.

war stimulated manufacturers and importers, and This is, of course, only a rough idea and sketch few. Machinery is needed only to pass a thread the improvements which were being constantly of what I believe might be done; but it is clear through the fabric, to retain this thread in the made upon them has tended to increase their use that if practicable, the speed may be greatly infabric after it has been passed through it, to fulness and their sale. In mechanical construction creased of all screw vessels, and perhaps also a change the relative position of the fabric and the they are rapidly approaching perfection ; but it is more efficient power be obtained of steering needle for the formation of the stitches, and to much to be regretted that the machines sold in straight astern.

J. H. SELWYN. tighten the thread in the fabric so as to form a

W. Crag, Grasmere, June 15, 1859. seam. Every combination of machinery which England had not been so far reduced in price as

to bring them within the reach of the middling effects these objects is a sewing machine.

THE EXPERIMENTAL SCREW There are five varieties of sewing machines : 1st. classes, and especially of families in moderate cir. cumstances,

PROPELLER. Embroidering, tambour, or chain stitch machines. 2nd. Running-stitch machines. 3rd. Compound

The annexed figure is an authentic representation

FISH-TAIL PROPELLERS. chain-stitch machines. 4th. Lock-stitch machines.

of the shape to which the propeller was reduced 5th. Back-stitch machines.

The following interesting letter is from the pen by cutting off its leading corner in the late exIn England, the first inventors of these varieties of Captain Selwyn, R.N.:-

periments made with the Doris. It will be perof the sewing machines, and the dates of their TO THE EDITORS OF THE “ MECHANICS' MAGAZINE.” ceived that by thus cutting in a straight line, ininventions, are as follows:- A tambouring, or GENTLEMEN,—I have read with much interest stead of rounding off the corner, two other chain-stitching machine, was first patented by your account of Mr. Reddie's paper read at the corners are formed, and the cut being across the John Duncan, May 30, 1804. A running-stitch U. S. Inst., May 30, and you will perhaps allow thickness of the metal in the blade, a blunt surmachine was first patented by Leonard Bostwick, me a few remarks on the subject.

face was left, which consequently met with April 2, 1814. A machine for making a compound Mr. Reddie is scarcely correct in assuming that greater resistance from the water than it would if chain-stitch, and also a lock-stitch machine, were the "fish-tail” form of propeller has been so much chamfered to an edge. That a blade of this in. first patented by John Fisher and James Gibbons, overlooked. It is mentioned in Appendix D), of December 7, 184. The first patent for a back the new edition of Tredgold's work, and indeed stitch machine was granted to Frederick F. Robin-few seamen who give their attention to such subson, February 7, 1851. Bostwick’s machine is jects have failed to observe and appreciate the extremely simple, and Robinson's is extremely admirable ease with which the ocean fishes, procomplicated; but as neither has been used to any pelled only by this means, are able to pass the considerable extent in this country, they deserve most rapid steamer when urged to her highest to be named only to make the list of varieties speed. My own thoughts have often been given complete. John Duncan and John Fisher are the to the subject; but the difficulty to be met is, or original inventors of the sewing machines used at I may say, I think, was this, that no backward present in Great Britain. All other patentees motion, no“ going astern,” so essential to steamers, have merely improved upon their inventions. could be obtained from such a form of propeller.

On the Continent several of these varieties were I now see reason to believe, however, that this perfect shape, with so thick a square edge, should used before they were patented in England. In apparently insuperable difficulty only arose from have proved its merits sufficiently to stand second France tambouring machines were used about the our not having studied nature quite closely in the order of merit of the propellers tried om beginning of the present century. A number of enough. In all those fishes (and there are many) that occasion would seem to amount to a proof the London Monthly Magazine, published in which are capable of rapid backing or stern mo that a blade torined, as Sir Howard Douglas pro1817, contains an allusion to an Austrian sewing tion, the breast fins or paddles are used for this posed, in a fair flowing curve throughout, with: machine, which may be quoted as a literary purpose, and there seeins no reason why we should the leading edge made fine, would be still more. curiosity :-"A Tyrolian has lately inyented, at not avail ourselves of the backing powers of the successful.

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BUNNETTS PATENT SELF-SUPPORTING FIRE-PROOF FLOORS, ROOFS, AND ARCHES.

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BUNNETT'S PATENT SELF-SUPPORTING | for the application of remedial measures. Many port from other blocks, the ends of each block FIRE-PROOF FLOORS, ROOFS, & ARCHES. plans have been devised for the construction of are also so cut as to give and receive a similar By W. BADDELEY, C.E.

fire-proof houses within the last half century, and support. The recent disastrous conflagration of an oil and I allude to the methods of constructing self-supof these, the last appears to be the most practical. Fig. 3 shows a floor composed of these blocks,

laid in cement, and farther held in position by tieturpentine warehouse in Linte-street has caused porting fire-proof floors, roofs, and arches, recently rods or bars B, at intervals, which pass through considerable excitement among the citizens, and

patented by Mr. Bunnett, the well-known builder's the hollow spaces formed within the blocks 4, to led to an inquiry as to the best method of pre-engineer, of Deptford. This invention was briefly plates of angle iron C; so that the entire thrust venting a recurrence of such a disaster. Two noticed in the annual report of London fires for of the arches is received and sustained by the rods things appear to be plainly demonstrated by this 1858 (ante page 206), and as it is now exciting and plates B, C. The end of the arches thus fatal occurrence, viz., that large depositories of much interest in the building world, the follow- produced may be built into walls, or carried by such highly-inflamrable materials ought not to ing additional particulars may probably be piers or other supports, according to the purpose be tolerated in such densely-crowded localities; interesting to your numerous readers.

to which it is to be applied, whether for the conand that all warehouses for containing such stores,

Bunnett's fire-proof floors are constructed of struction of floors, or roofs of houses, bridges, &c., wherever located, should be of fire-proof con-hollow or cellular bricks, so formed, externally, as &c. In Fig. 3 the floor is slightly canted, which struction. Had the building where this unfortunate but laid to break joints, each brick receives the direct to lock into each other on all sides, so that, when would, for many purposes, be thought advan

tageous; but Fig. 4 shows the method of propurely accidental calamity took place been com support of six adjoining ones, carrying out a prin-. ceeding when a flat-boarded floor is to be laid upon posed of incombustible materials, with such well. ciple of mutual support over the whole extent of the arch with a ceiling underneath, known adjuncts as science furnishes for the pur- the floor.

In this case the tie-rods, B, are shown as passing pose, it is almost certain that the contents of one

Figures 1 and 2 show a transverse and longi- below the bricks (instead of through them), and floor only would have been consumed, without tudinal section of one of these cellular bricks made through the walls, forming supports for the any damage to the surrounding properties. As it of clay or brick earth; they are produced by' ceiling joists. was, the vast amount of combustible matter em forcing the plastic clay through dies or moulding' Fig. 5 shows a fire-proof floor, or roof, conployed in the construction of the building literally orifices, the dies being so forined as to cause each. structed of graduated cellular bricks, with a cenadded "fuel to the fire,” increasing the fury of block to be produced with two of its sides of a tral key-brick, forming a perfectly flat floor on the the flames and extending their ravages in all di- suitable shape to overlap and be overlapped by the upper surface, but arched on the underside. rections around.

adjacent bricks. The form of the overlapping: are the blocks, B the tie-rod, and C the angle Although it is admitted that it is almost prac. parts a a may be varied, but it is believed that : iron wall plates. tically in possible to construct an absolutely fire the form of block shown above is as convenient a: 1 Fig. 6 is a section of one of the graduated proof building, still much may be done by a

any for the construction of floors and roofs of cellular blocks employed in the construction of the judicious disposition of even combustible mate. fire-proof character.

floor, Fig. 5. The advantages of these fire-proor rials,* to retard the progress of fire and give time

In addition to the two sides of each block being s floors consist in the facility and cheapness with

made so as to give support to, and receive sup which they can be constructed; their capacity to “There is a description of floor, which although not

resist and remain unaltered by heat; their great altogether fire-proof, is almost practically so. It is com- tight. Its thickness and its property of being air-tigh posed simply of plank 2 or 3 inches thick, so closely joined will be easily observed to be its only causes of safety:

strength, and fitness for the reception of wood and so nicely fitted to the walls as to be completely air

Braidwood on Fire-engines floors, cement, plaster, imitation of marbles, or encaustic tiles, in which case they will not exceed

SCOTT'S MAXIMUM THERMOMETER. in thickness an ordinary floor with joists.

Arches upon this principle are well adapted for cheap and durable bridges of a moderate span, as well as for beams, girders, &c.

Persons desirous of availing themselves of this admirable invention will do well to visit Mr. Bunnett's works at Deptford, where practical demonstrations of the strength and capabilities of floors of this description may be seen and tested.

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SCOTT'S
COMPENSATION SELF-REGISTERING

MAXIMUM THERMOMETER,
FOR DEEP-SEA OBSERVATIONS.

B
MR. WENTWORTH L. Scott, of Brunswick-terrace,
Westbourne-grove, has favoured us with the fol-
lowing description of his thermometer for deep-
sea observations, which was exhibited at this year's Zelo

A Exhibition of Inventions at the Society of Arts.

This instrument consists of a glass tube with a cylindrical bulb containing mercury (as in the ordinary thermometer) at its lower extremity ; but at the top the stem is drawn on into a fine jet, bent at right angles, A, Fig. 1; in the inte. rior of the second bulb, B, Fig. 1, this upper bulb is about half filled with mercury, the remaining space being a vacuum; near its base a platinum wire, p, iš welded into the glass and bent up. wards so that its point is nearly in contact with that of the jet. It is obvious that when the in. strument is "set," i.e. the lower bulb and capillary tube to the point of the jet completely filled with mercnry—any rise of temperature will expand the mercury and cause it to overflow in minute globules into the reservoir above. The platinum wire is simply for the purpose of preventing the

15 formation of large drops at the point of the jet, by its superior attraction for the fluid metal. Upon cooling, the mercury now remaining will of course sink in the tube. The instrument is so graduated that if it were cooled to 0 deg. Fahr, the level of the mercury would precisely indicate the highest temperature to which it had been previously exposed; but if the observation were made at the atmospheric temperature the mercury would stand exactly as much higher in the tube, i.e., lower in the scale, as the temperature of the air was above O deg. Fahr.; therefore to ascertain the maximum temperature it is only necessary to add to the degree at which the mercury stands the temperature at the time the observation is made. Thus, supposing the “compensation" thermometer marks 35 deg., and an ordinary instrument by its side is at 50 deg., 85 deg. will be the highest temperature that has occurred since the last observation. To “set” this thermometer, the lower bulb must be gently raised until the mercury runs down the tube into the reservoir-bulb; when contact has thus been established between the two portions of the metal, the reservoir-bulb is slightly elevated, care being taken to keep the point of the glass jet under the sun-face of the metal (the dotted line aa in the diagram represents the level of the mercury during this operation). The mercury will now flow back into the lower bulb and refiil the small vacuum produced by the previous decantation, when, upon restoring the instrument to its original vertical position, the tube will be full to the extreme point of the jet. It will be at once seen that vibration or agitation cannot militate in the Society of Arts has recently been awarded to the rough. They have afterwards to be finished up, any degree against the accuracy of this instru- the inventor for this instrument. It has also and pass through several hands. M. Combarieu, by ment, no moveable indices being employed. Fig. been examined and approved by Rear-Admiral R.

an ingeniously invented machine, produces 10,000 of 1 gives a view of the upper bulb, and a portion of Fitzroy.

these characters at one stroke. Each letter is then the scale, of the actual dimensions. Fig. 2, one

separated by a mechanical saw, which divides them third full size, shows a section of the entire

with mathematical regularity and precision. The

In a late number of the Morning Star we read:- consequence of this invention will be-production instrument in a gun-metal tube for deep-sea “ The invention of the myria-type of M. Combarieu increased cent. per cent.; exactitude and regularity, experiments. Fig: 3 is an external elevation. has been submitted to the Government and accepted hitherto unattainable ; the use of harder metal, which The thermometer is "set,” and inserted in the for inspection. This marvellous invention being will avoid the frequent renewal of printers' materials ; tube (into which, after grensing, a little mercury destined to operate an immense and immediate reduction (by one half) of the outlay; and at length has been poured), oscillation being prevented by revolution in the art printing, it is worth description. the ono great object-an increase of printing, and an rings of vulcanised india-rubber, the upper one

Hitherto the characters used in printing have been enormous diminution in the price of books! Look clainped by the binding screws 6 b; lastly, the characters, by reason of their extreme softness, wear behold the glorious result

. M. Combarieu announces, composed of a mixture of lead and antimony ; these now through the vista of approaching years and cap is tightly screwed on, the arrangement being out quickly, and are, besides, very expensive. The moreover, his intention of producing characters in then ready for use. Well greased leather washers characters are moulded one by one; the best work steel, the durability of which will be beyond calcula. occupy the spaces at ww. The silver medal of man can scarcely produce 5,000 of them in a day in |tion."

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Literature.

an imperfectly insulated wire, to escape to this an important extension of the original plan has plate by the shortest route, in lieu of completing been effected with regard to the return current,

the circuit through the second instrument and the necessary to deflect a needle in either direction. To The Globe Telegraph: an Essay on the use of the positive plate ; and hence the loss of electricity obtain this return current it is proposed to employ

Earth for the Transmission of Electric Signals. which invariably occurs in this system according a metal intermediate in its voltaic character to By Septimus BEARDMORE, C.E., F.R.G.S. Lon to the tension" power of the battery. In the the copper or platinum on the one hand, and to don, 1859. Edward Stanford, Charing Cross.

method proposed by the inventors of the globe the zinc on the other. A plate of iron is found In July of last year, when telegraphists, perplexed telegraph, these conditions are altered, as will be to fulfil this condition, transmitting a positive with induced currents and earth currents, losses seen by a glance at the diagram, No.2:

current to the zinc and a negative current to the of insulation, and consequent losses of electricity, were far from sharing in the unmingled exultation

It is evident that the current can here have no copper. For a full explanation of the arrange. with which the public of two great nations re- tendency to the plate whence it flows, since it ment by which the three metals at either side are ceived the news of their electric union, an amateur cannot complete the circuit without passing employed to produce the reverse signals we refer student of electricity applied himself to the conthrough the second instrument and the opposite our readers to the specification of the patent, or

to Mr. Beardmore's pamphlet. sideration of the various difficulties of occan tele- plate. Hence it was at first assumed by the in

The necessity of diminishing the resistance graphing, and arrived at a definite idea of the means ventors of the globe telegraph that insulation of

offered to the transmission of the current by the whereby they might be overcome. This gentle the conducting wire was unnecessary: But, as man, M. Hoga, in conjunction with Mr. Piggott

, uninsulated. would become an element in the nised.
was soon ascertained by them, the wire, if left telegraphic wire is beginning to be fully recog.

It is of little avail, however, that the well-known for his application of electricity as a medical agent, and with the author of the presentment at the station, and rendering the transmis creased, if long coils of fine wire are to be em.

voltaic arrangement, replacing the positive ele- diameter of the main conductor should be in. pamphlet, cominenced a series of experiments, which, though, begun on mistaken grounds, soon sion of signals impossible.

ployed in the instrument through which the assumed a scientific character. The principle on In the lines established at the period of Mr.

current takes effect. As no wire can be stronger which these experiments were based, and which Bain's experiments, the loss of electricity in the than its weakest part, so must its power of conthey served to confirm, was one which was not existing method of working telegraphs was of ductibility depend upon its least-conducting pornew in the science of electric telegraphy; though little moment. In the longest submarine circuit tion; for any impediment in one part of an elec

tric circuit must influence the total amount of the experimenters, like many others who have of the present day, however, this loss of power laboriously explored what was already mapped out and the induction charge caused by the electric electricity that can be transmitted. With currents and described, were perfectly unaware of its tension, have been fatal to the success of the of high static intensity, a long coil of fine wire is having been previously investigated and even undertaking. And, though the tension may in requisite; a short coil of thick wire being scarcely made the subject of a patent. Nevertheless, so this system be reduced to a certain point, yet the influenced by electricity in this condition. On the far back as 1843, Mr. Bain had secured the appli- conditions which determine the escape of the other hand, with dynamic currents of low intencation of simple, positive, and negative plates for electric fluid cannot be altered without having sity, the contrary is the case; a single turn of telegraphic purposes; which plan, having been recourse to the current produced by the single coils are scarcely affected. With the increased relinquished by the original inventor, was now couple of positive and negative elements. adopted, and ultimately considerably extended, It has been asserted, but without sufficient in the new system, increased facilities for effecting

necessity, therefore, of diminishing the resistance by the new experimenters, as a means of obtain proof, that tension electricity is necessary to over ing an electric current of low “intensity” and come the resistance of a wire to the transmission

the same are also presented, and will doubtless be considerable quantity, in which the loss from im of the current. An idea was also prevalent, and profited by: It is to be hoped that no time wiļl perfect insulation, and the retardation from an appears to have been received by Mr. Bain, that ments are made to determine the practical value induced charge, should be reduced to their the surface of the plates in a simple galvanic of an invention which appears to be called for by minimum. On the 17th November, 1858, Messrs. arrangement requires to be rapidly augmented in Hoga, Piggott, and Beardmore took out a joint proportion to the distance between them. The point of cheapness is but a secondary considera

the requirements of the times. Its advantage in patent for • Improvements in Electric Tele- ratio in which this increase is necessary has now graphs,” in which, acknowledging the prior claims been ascertained to be in accordance with the evidence tends to prove the difficulties which have

tion, if it meets, as the primâ facie theoretical of Mr. Bain, as originator of the groundwork of square root of the increase of distance. Thus, it been so fatal to the success of the Atlantic cable. the system, they secured to themselves the dis- one square inch of the metals produce a certain covery of the means by which it might be brought deflection of the galvanometor at a distance of 10 into practical use. feet, 2 square inches will be sufficient to pro Beardmore's The Globe Telegraph, 5s. 6d.

LIST OF NEW BOOKS. Although the value of this system is a matter duce the same deflection at a distance of 40 feet, Burgoyne's Military Opinions, &c., edit. by Wrottesley, 14s. to be determined by extended experiments rather and 8 square inches will have the same effect Field Exercise and Evolutions of Infantry, 1859, 3s. (d. than by theoretical arguments, we will place when the plates are 640 feet apart. And thus, to Gwilt's Encyclopædia of Architecture, 42s. before our readers a brief aperçu of the more mani. work the cable between St. John's and Valentia, a

IIerbert's The Sanitary Condition of the Army, Is. 6d. fest advantages to be looked for in its application. surface would be required of less than 7 square logg's The Microscope : its llistory, os.

Herschell's Manual of Enquiry, 3rd edit., by Main, 93. The following diagram, No. 1, represents the feet of each metal. With regard to the resistance Household Encyclopaedia, vol. 2, 135. 6d. existing mode of employing electricity for tele- of a wire to the transmission of a current, which

Hunt's Universal Yacht List, 1859, 4s.

James's Naval History of Great Britain, new cd., vol. 2, 5s. graphs :bears an inverse proportion to the diameter of the Kennedy on Defences of Great Britain and Ireland, Is. 6u.

Manual of Punctuation, by a Practical Printer, Is.
Maury's Physical Geography of the Sca, new edit., 5s.
National Cyclopædia of Useful knowledge, 5s.
Our Naval Position and Policy, 123.
Philp's History of Progress in Great Britain, 7s. 6d.
Reid's Mental Arithmetic, Is. 3d.
Remarks on Coinage, with Decimal Coinage, ls.
Tomlinson's Thunder Storm, 3s. 6d.
Volunteer's Handbook, ls.
Ward's Telescope Teaching 7s. 6d.

DIAGRAX No. 1.

VSATTERY

THE NEW IRON STEAM RAM.
The following article, which we take from the

Times, of yesterday, contains fuller information
DIAGRAX No. 2.

on some points respecting the Government iron steam frigate than has yet appeared :

The English Government have very wisely determined to build a wrought-iron vessel of immense size, strength, and steam power, specially adapted as a vessel of war, and for running down ships of the largest kind, not even excepting the Great Eastern itself. The contract for this tremendous engine of modern war has been taken by

the Thames Iron Shipbuilding Company, and suffi. As in the method presently to be described, one conductor, it is apprehended that there would be cient progress has been made with the ironwork half of the circuit is here completed by the earth little difficulty in increasing the size of the wire, to be used in her to make it ccrtain that she will in the direction of the lower arrow; the earth should this be found necessary, to a very consider. be afloat and fitting for sea by June next. Her plate” at the zinc end being negative, and that able extent.

dimensions will be-extreme length, 380 feet; terminating the wire positive. From the dissimi. The above diagram, No. 2, represents Mr. breadth, 58 feet; depth, 41 feet 6 inches; and her larity of the electric character of the wire and of Bain's arrangement, which also forms the ground tonnage no less than 6,177 tons. The weight of the earth-plate at the battery-station, results a work of the system now proposed by the patentees the empty hull will be 5,700 tons. The engines constant tendency of the current, transmitted by of the Globe Telegraph.In this system, however, are to be by Penn and Sons, of 1,250-horse power,

wave

once

and of these we shall give a description on another neck and breast of a swan when swimming. Thus disengaging hook only, which would be simply occasion. Their weight with boilers will be 950 the point which would strike an enemy's vessel ridiculous. Four men is certainly no over esti. tons; she will carry 950 tons of coal, and her ar. was the “breast,” which was placed under the mate when he himself admits that the usual number mament, masts, stores, &c., will amount to 1,100 water line. In the Admiralty model, ac- are reqnired on board to lower, with one man to tons more. Thus at sea her total weight will be cording to which the “ram” is to be built, disengage; printed directions furthermore stat. about 9,000 tons, which will be driven, when so the bows form an obtuse angle, the point of ing, that “the foremost disengaging fall may be wanted, through the water against an enemy's which is just level with the water, receding back kept handy ; but it should only be used as a reship at the rate of 16 miles an hour. It is difficult at a rather sharp slope both above and below it. source to provide against the extreme possibility by mere description to give an adequate idea of This peculiar shape, however, will be concealed of the aftermost line being foul, which latter is the tremendous strength with which this vessel is under the usual figurehead and forward gear with hardly possible." This would involve the necessity to be built. The keel, or rather the portion to a light artificial cutwater of wood, so that ap. of the presence at least of a second for disengag. which the ribs are bolted, is made of immense parently the vessel will be an ordinary frigate of ing. "Nauticus” further states," whether the men slabs of wrought scrap iron, an inch and a quarter the largest size. The Admiralty, no doubt, intend lower simultaneously or not, directly the disen. thick, and three feet six inches deep. From this by these devices to disguise her real character, gaging line is let go the boat must enter the water spring the ribs-massive wrought iron T-shaped but we need hardly point out how utterly futile on an even keel." What is to prevent one fall beams, which are made in joints about five feet such an attempt would be. Could any naval going, with a run? a common consequence of long by two deep, up to where the armour plates officer be deceived by any amount of painting lowering by the falls, which no system of disenbegin, five feet below the water line. These beams about the character of a ship of 6,000 tons, gaging can remedy. To the first objection, that are only 3 feet 8 inches apart, while, for a dis- nearly 400 feet long, rigged like a three-decker, the length of the pendants cannot be suited to tance of 10 feet on each side of the keel, they are yet only carrying a broadside of 14 guns on her light and heavy draughts, the reply is, they are bolted in at only half this distance asunder. Five main deck ? Or do the Admiralty suppose that adjusted so as to enable the boat to reach the feet below the water-line the armour plates com- there will not be perfect photographs of her, when water when the ship is laden, but extra rope is mence, and, to give room for these, the depth of the finished, taken for all the foreign powers, which allowed for light draughts, as my printed direcrib diminishes to about half, or nine inches. Over will be reproduced and distributed among their tions explain. In men-of-war the difference in the ribs, and crossing transversely, are bolted navies, with strict injunctions in case of war draught with couls or without is so slight as to beams of teak a foot and a half thick, and outside always to avoid such a vessel if they can ? The very be of no consequence in this matter, and the these again come the armour plates. Each of idea of attempting to conceal the real purpose of additional rope on the roller could not lead to these plates is to be 15 feet long by 4 feet broad a vessel so remarkable, and the only one of its accident. In a line-of-battle-ship the extreme and 4 inches thick. Several of them have been kind afloat, seems absurd. Coming up into action variation of draught would be 20 inches; in ships inade by the company of puddled iron, of an. with other first-rates in line of battle, no doubt of the “Diadem” class, 2 feet; and in gun-boats nealed scrap iron, and of scrap iron unannealed, she would pass muster unobserved, but under such 6 inches. From the way in which the boat hango, and experiments are now being made at Ports- circumstances, even if as well known to the enemy by my system (the points of suspension head and mouth with a view of testing practically which as to the English, the knowledge would avail stern being above the boat's gunwale, from which best withstands the tremendous attack of 68- nothing to the former. Once a general engage steadying lines to the boat's sides are attached), pounders. It is almost needless to say that each ment was commenced, the “ram” would be able she would not be swamped as a boat is ordinarily plate is the very perfection of material and manu- to pursue her mission of destruction by running under such circumstances, if the water were facture. These ponderous slabs go up to the level into the sterns of the enemy's vessels almost with moderately smooth, and if rough, the fall of the of the upper deck. The orlop deck will be of wood, out hindrance. When such is avowedly her pur

would at

clear the pendants. and 24 feet above the keel. The main deck will pose it seems to say he least, unwise to cumber her " Nauticus” cannot tell me of any instance of a be of iron, cased with wood, and 9 feet above the with the masts and rigging of a line-of-battle boat “having been swamped and her crew proorlop. The upper deck will also be of wrought ship. The shock of striking the first vessel would Lably drowned,” nor can he produce the instance iron, and 7 fect 9 inches above the main. All the bring down all her masts by the board like which he “fears might be cited.” decks are carried on wrought iron beams of the reeds, and leave the ram's decks so encumbered One of the chief features of my system of dismost powerful description, to which both the with wreck as might even render her almost engaging, and to which I attach very great impor. ribs and iron decks are bolted; while along the useless for further efforts. The mode in which tance, though the one least understood till seen whole length of the vessel, from stem to stern, she attacks will be to run straight at the enemy, in actual operation, is that when the boat is are immensely solid wrought iron beams at inter- taking him, if possible, in the stern or quarter, all lowered, steerage way is not only put upon her vals of five feet inside the ribs, which are again the men on deck retiring to the stern to avoid directly she touches the water, but is retained for crossed by diagonal bands, tying the whole to injury from falling spars. When about half the several seconds after she is floating by a gradually gether in a perfect network. The armour plates vessels length from the enemy the engines are to yielding strain without any sudden check or addi. are not intended to shield the whole vessel, only be stopped, and the engineers' stand by to reverse tional act of any one to release the boat. This the fighting portion, about 220 feet of the broad the engines in order to clear her from the wreck enables her to be sheered clear of the ship, and side, being thus protected. This broadside, how of her antagonist before the latter goes down. It out of the suction of the screw. The loose tapered ever, will mount 14 of the Armstrong 100lb. is calculated that striking a line-of-battle ship in end of the pendant as it is overhauled through the guns, which, with two broadside guns on the the stern the ram would sink her within three three sheeve blocks accomplishes this end, either upper deck and two pivot guns of the same kind minutes. The bowsprit will, we believe, be tele. by the strain caused by the way of the ship, or forward and two aft, will give her a total arma- scopic in order to be housed on board with the if at anchor, as the boat falls with the wave or ment of 36 guns, each throwing a 100lb. shot anchors before striking the enemy, that there may is drifted away. Without some such provision, over a range of nearly six miles. Neither the be no chance of becoming entangled with the lowering a boat from a screw steamer under way, bows nor stern have any of the large armour wreck of the sinking vessel. It is, however, yet especially on the weather quarter in a heavy seaplates, but are coated with wrought iron plates of to be explained how she is to get rid of her own way, would be a dangerous experiment, the wind nearly one inch and a half thick over two feet of wreck of masts and spars, and above all what pre- and draught of the screw carrying the boat diteak, which will offer sufficient resistance to precautions will be adopted to prevent any chance rectly on to the latter. But this I have repeatedly vent most shots from going through. But to of the rigging fouling her screw. The cost of the done on public trials. compensate for this apparent deficiency both bows hull will be about £200,000, the engines about As to the boat being stove against the ship's and stern are so crossed and recrossed in every £75,000, and her fitting for sea about £45,000 side, the celerity obtained by lowering with single direction with water-tight compartments that it more-or £320,000 in all. If she only does one- pendants is the best possible prevention to such a is a matter of perfect indifference whether they half of what may be fairly anticipated from her casualty ; for when lowered and disengaged at get riddled or not, and each of these ends are shut she will be cheaper to the nation than a dozen sail the same time by one hand only, advantage can be off from the engine-room and fighting portion of of the line, and we hope before long to announce taken of the roll of the ship, and the boat be the ship by continuous massive wrought iron trans. that another of the same kind has been decided on. dropped on the water clear of the ship in a few verse bulkheads. So that, supposing it possible that

seconds after the word of command is given to both stem and stern could be shot away, the centre of the vessel would remain complete and impene

CLIFFORD'S SYSTEM OF LOWERING

“lower away,"if the gear is only kept in the same

condition as the rest of the running gear of the

BOATS. trable as ever, still offering in all 24 inches of teak

ship. This cannot be done where the combined coated with 5 inches of wrought iron to every

MECHANICS' MAGAZINE." action of several men is required, as in lowering shot. But both stem and stern are built inside of GENTLEMEN :-I must beg space in your by the falls. such immense strength that coating with armour columns for a reply to the objections urged by As to the stiffening of the pendants, the samo plates would be almost superfluous. The bows, as “Nauticus" against my system of lowering boats, causes that would prevent their working would the spot where the whole shock must be received as they are evidently made by one who does not operate against the falls; and if the pendants, in running down ships, are inside a perfect web of understand the principles of the system, or know from being of stouter rope, offer greater resist. ironwork, strengthened back to the armour plates how to work it properly. Before answering these ance to a free run, the direct action of the weight with no less than eight wrought iron decks an I would remark that the impression evidently in of the boat on the pendant or the single part of inch thick, and crossed and recrossed in all ways tended to be conveyed by the report in the l'imes rope only that they involve, in place of the four and methods with diagonal bracings and sup. could only be that the operationreferred to as re- parts of rope used in the falls, is a proportionato ports. In the design sent iato the Admiralty by quiring four men was that of the " system of lower power to overcome such resistance. the Thames Shipbuilding Company the shape of ing invented by Captain Kynaston" mentioned in The “vibration” complained of in lowering could the bows was made exactly after the outline of the I the sentence immediately preceding, and not the only arise from the gear being improperly rove,

TO TIB EDITORS OF THE "

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