with the fluid metal, during the process, and the quantity of phosphorus was thereby reduced. Thus many months were consumed in laborious and expen. sive experiments; consecutive steps in advance were made, and many valuable facts were elicited." the allusions which Mr. Bessemer made in his nufacture of the world. The specimens of metal | These cylinders were drawn from a round castrecent lecture to the difficulties which have produced by his improved processes which were iron ingot of only two inches greater diameter opposed the successful application of his inven- exhibited at the Institution of Civil Engineers than the finished cylinder, and in the precise tion. He says:— on the evening of his late lecture, and subse-way in which a gun would be treated; they "The want of success which attended some of the quently at the President's conversazione, deserv- may, therefore, be considered as short sections early experiments was erroneously attributed by some edly elicited much praise, and afforded mani- of an ordinary 9-pounder field-piece. The tenpersons to the "burning" of the metal, and by others fest ground for many of the hopeful statements sile strength of the samples, as tested at the to the absence of cinder, and to the crystalline con- made on the first of these occasions, and pub- Royal Arsenal, was 64,566 lbs. per square inch; dition of cast metal. It was almost needless to lished in the abstract lately given in our while the tensile strength of pieces cut from the say that neither of the causes assigned had anything columns. to do with the failure of the process in those cases Mersey gun gave a mean of 17,550 lbs. longituwhere failure had occurred. Chemical investigation It is a most gratifying thing to know dinally, and 43,339 lbs. across the grain; thus soon pointed out the real source of difficulty. It was that we have now put into our hands a showing a mean of 17,550 lbs., per square inch in found, that although the metal could be wholly de-homogeneous malleable metal which may be favour of the Bessemer iron. For the accuracy of carbonised, and the silicum be removed, the quantity of sulphur and of phosphorus was but little affected; cast into any desired form, and which leaves these figures Mr. Bessemer is responsible. If it is and as different samples were carefully analysed, it the mould free from cracks, flaws, hard veins, desired to produce ordnance by merely casting was ascertained that red shortness was always pro- &c., and is at the same time of enormous tensile the metal, the ordinary founding process may duced by sulphur when present to the extent of one-strength. Several samples of the Bessemer be employed, with the simple difference that tenth per cent., and that cold shortness resulted from steel tested in the proving machine at Woolwich the iron, instead of running direct from the the presence of a like quantity of phosphorus; it, Arsenal bore, according to the reports of Colo-melting furnace into the mould must first be therefore, became necessary to remove those substances. Steam and pure hydrogen gas were tried, nel Eardley-Wilmot, R.A., a strain varying from run into the converting vessel, where in ten with more or less success, in the removal of sulphur, 150,000 lbs. to 162,900 lbs. to the square inch, minutes it will become steel or malleable iron, and various fluxes, composed chiefly of silicates of the and four samples of iron boiler plate from 68,314 and the casting may then take place in the oxide of iron and manganese, were brought in contact lbs. to 73,100 lbs. ; while according to the pub- ordinary manner. Conical masses of this pure lished experiments of Mr. Fairbairn, Stafford- tough metal, of from 5 to 10 tons in weight, can shire plates bear only a mean strain of 45,000 be produced at Woolwich at a cost not exceedlbs., and Low Moor and Bowling plates a meaning £6 12s. per ton, inclusive of the cost of of 57,120 lbs. per square inch. There is also pig iron, carriage, remelting, waste in the proHere we are sneeringly told that neither of another fact of great importance, as we are re- cess, labour, and engine-power. These importhe causes assigned by disinterested persons for minded, in a commercial point of view. In the tant facts have been laid, we are told, before Mr. Bessemer's failures in 1856 had anything to manufacture of plates for boilers and for ship- the Government, and their advantages are do with those failures; and we are further told building the cost of production increases con- stated to be fully appreciated by Colonel Eardthat the true cause was the presence of sulphur siderably with the increase of weight in the ley-Wilmot, the Superintendent of the Royal and phosphorus in the metal produced, the air plate; for instance, the Low Moor Iron Com- Gun Factories, who has evinced a great interest blast having but little effect upon these impu-pany demand £22 per ton for plates weighing in the progress of the invention from its earliest rities. But what are the facts? One of the 2 cwt. each; but if the weight exceeded 5 cwt. date. earliest adverse criticisms of Mr. Bessemer's then the price rises from £22 to £37 per ton. paper which appeared was an article contributed Now, with cast ingots such as the one exhibited to the MECHANICS' MAGAZINE of September 13, which the sample plates were made, it was less at the Institution by Mr. Bessemer, and from 1856, by Mr. William Truran, the author of an admirable volume on "The Iron Manufacture troublesome, less expensive, and less wasteful of Great Britain;" and in that article the of material, to make plates weighing from 10 to author distinctly pointed out the fact that Mr. 20 cwts. than to produce smaller ones; and, Bessemer's process did nothing towards the reindeed, there was but little doubt that large moval of the sulphur and phosphorus from the plates would eventually be made in preference, metal. "Mr. Bessemer committed a great and that those who wanted small plates would "mistake," said Mr. Truran, "when he claimed have to cut them from the large ones. A "for his plan the production of that quality moment's reflection therefore shows the great "known as charcoal iron, simply from the re-economy of the new process in this respect; "fining being conducted without contact with and when it is remembered that riveted every "mineral fuel. A superficial acquaintance with joint in a plate reduces the ultimate strength "the subject would have shown that the quality of each 100 lbs. to 70 lbs., the great value of long plates for girders and for ship-building will be fully appreciated. "of the fuel used in the manufacture of a 66 66 66 EXPLOSIONS AT GUNPOWDER Ir is desirable, we think, before the memory "Mr. Rowse stated that he was about 90 yards off at the time. It was the lower press exploded first. Could not say whether the treble dust was brought into the press-house over night, or whether more in the morning was taken in a boat; could not say how much there was on the premises the day before. The Nor can we leave this subject without re-pressure is taken off by letting the water off directly. The powder was pressed enough. Takes about five minutes to move the powder from the press. Cannot remember how much in the press-house the night before. Might have been fifty barrels. Could not week on the premises. state there was not eight hundred barrels made per moiety of the bar-iron, so far as regards the "usual contaminating ingredients, sulphur and "phosphorus, has nothing to do with the ulti-ferring, at the risk of repetition, to the wonderful "mate quality of the bar." And again the promises which the Bessemer process holds out same gentleman, in an article which appeared in to us in reference to the manufacture of ordthe MECHANICS' MAGAZINE of the following nance. Many attempts have been made to month, said :-" It is questionable if one single produce wrought-iron ordnance, and this object "atom of phosphorus or sulphur was separated has been successfully accomplished in the case "[in Mr. Bessemer's experiments], for the re- the large gun produced at the Mersey forge. "sults of analysis are altogether against a more But, however perfect this one gun may be, the "favourable conclusion. Phosphorus and sul-time required to make it, and its immense cost, "phur exist to the extent of 14 per cent. in manifestly render it still, as Mr. Bessemer stated, many pig-irons, and their removal is essentially a great desideratum to produce guns rapidly and necessary to the production of good malleable cheaply, of a material equal to, or greater in ten"iron." How Mr. Bessemer could have gone on sile strength than wrought iron, and, if possible, pottering at chemical analyses in order to disco- free from the liability which that material has ver facts which a sound practical iron-maker to flaws and to deterioration during long expowas thus clearly placing before him, or how he sure to a welding heat. It is believed that the can now have the effrontery to sneer at those Bessemer process supplies this desideratum, as who were taking pains to teach him what he masses of cast malleable metal can be produced was so manifestly ignorant of, we are at a loss of ten or twenty tons in weight in a single piece, and two or three such pieces may be conveniently made by the same apparatus in one day. The metal so made may be either soft malleable iron, or soft steel. In order to prove the extreme toughness of such iron, and the strain to which it may be subjected without bursting, several cast and hammered cylinders were placed cold under the steam hammer, and crushed without the least tearing of the metal. to conceive. But while we may look to Mr. Bessemer in in vain, we fear, for any manly recognition of his own shortcomings, or any grateful acknowledgement of the aid which others offered him, and while we must receive with caution all that he comes forward to say in commendation of his own proceedings, we have no wish to deny that he has at last done good service to the iron ma "Mr. Ashby, the manager of the works: Had not any farther information to give as to the cause of the accident. Was now constructing the press in a very with 20 feet of earth over. different manner with transverse arches, bomb-proof, between the press-house and the place where the men This wall or fence to be would work the pumps for the hydraulic pressure. The new press to carry eight barrels instead of double that quantity, as was the case in the late press. There was a Government inspection by two military for Government contracts. The firm had existed 35 officers to ascertain the quality of the powder making years. The mills had been in existence one hundred years. Should not have a water-tank over the new press-house. Considered it caused the great lateral explosion. It was his decided opinion explosions were unavoidable. Had increased the number of mills on the premises by five in the last fifteen years. Had sworn that 400 barrels on an average was the quantity made on the premises at Twickenham per week. Had no reason from subsequent inquiry or other means to alter that statement. Would not swear there was not eight hundred barrels per week exploded after the press-house, there were three men made on the premises. In the corning-house, which employed. The quantity of powder usually there was from ten to fourteen barrels. In the green charge, or what was now called incorporating houses, forty-offices must be a sinecure-perhaps placed under | occurred in January last to the spiral staircase two pounds of powder only at a time; forty pounds being allowed by Act of Parliament, and two pounds for waste. In the glazing-house there are about twenty barrels at a time. One-third of the powder glazed at Twickenham works came from the Bedford Mills. "Henry Atlee: Is a glazing man. Had been much injured. There were one hundred barrels of pow.ler in the glazing-house at the time of explosion; sometimes there are as many as three or four hundred barrels, sometimes only twenty. On the day before the explosion he was in the press-house; saw two hundred barrels there. Forty-nine barrels had been removed from the corning-house to the glazing-house during the morning previous to the explosion. Had no instructions as to quantity of powder to be in the glazing-house at once. Glazed one hundred and thirty barrels a day in both houses. Three men employed. Sometimes glazed more, sometimes less. That was the quantity expected to be done. Worked on Sundays as on other days. Quantity of powder taken into the green charge or incorporating-house was a hundred-weight at a time. Should return to the mills when sufficiently recovered." We make no reference here to the evidence of Mr. Taylor, the former engineer to the works, -who left, by his own admission, from his some comfortable arrangement which makes has effectually crippled, as we lately intimated, Mr. Ashby's statement that the proprietors of the works had determined upon constructing the press in a different manner to carry eight instead of sixteen barrels, is a tacit admission that his own judgment is at variance with that of his employers. We are still disposed to think that even the raising of the mound " upon transverse arches and rendering "it bomb-proof" will not afford sufficient protection for the men, unless the conditions of the Act of Parliament and the presumed regulations as to the prescribed quantity of powder to be admitted under the roof at one time be On public grounds we venture to press the strictly adhered to-bomb-proof not being ne- case of the Polytechnic upon the serious and imcessarily gunpowder proof. Mr. Ashby's "de-mediate consideration of public philanthropists." "conviction that the several alterations at the cided impression that explosions are unavoid- No time is to be lost. A few days will either "works were of a most dangerous description" "able" we consider a most important and consign the noble premises to mercantile ends, if --because that evidence, given without solicita injurious admission, since it partly discredits not to objectionable purposes still more at variance tion to many persons ex judicio, does not ap-ties; and in the very front of so bold and scientific and religious public interpose their coattempts to mitigate or suppress these calami- with the design of the Institution, unless the pear to us to agree with that rendered by him before the Coroner. We will therefore leave mischievous an assertion we have lately had in operation to restore it to its wonted uses. Mr. Taylor out of our future comments, merely our own columns the testimony of one of the reproducing a remark openly made in court, in the world, where, as a consequence of judilargest firms for the manufacture of gunpowder that Mr. Taylor's evidence would appear to "have been more valuable out of doors than cious forethought, and the adoption of "very "in." It may appear strange that the im- "many improvements," a fatal accident has not portant portions of the inquiry, as given above, occurred for twenty-five years. This dogged should differ so widely from the accounts which refusal to adopt remedies for the prevention appeared in most of the daily and other jour-of the sacrifice of "hands"-for such is the nals. Our notes were, however, taken by an especial hand, and we have great reason to confide in their integrity and truthfulness. It will have been already observed that while Rowse could not swear there were not 800 barrels made per week, Ashby states there were conventional term now applied to working men THE CASE OF HENRY CORT, AND OF BRITISH IRON. BY THOMAS WEBSTER, M.A., F.R.S., &c., Barrister-at-Law. No. IV. THE specifications recently published by Mr. Woodcroft, under the authority of the Commissioners of Patents, show that the inventive during the first half of the 18th century, to the genius of the country was directed principally, addition of materials and ingredients, and the but 400, but would not say there were not 800,/ture of gunpowder a reason for some change; and adoption of fluxes for facilitating the melting moment to infer that the Act has not been time. as the conditions of one of its Acts has already and Atlee gives the quantity glazed as 130 been grossly violated, it needs no extraordibarrels per day-equal, as the work is carried on upon Sunday, to 910 barrels per week! Mr.nary excuse for an immediate and searching Ashby further states that the greatest quantity kept in the corning-house was from ten to fourteen barrels. Atlee tells us that forty-nine barrels had been moved to the glazing-house from the corning-house during the morning of the explosion. Mr. Ashby further states that forty-two pounds was the quantity allowed in the incorporating-houses, according to Act of Parliament, and we are left for the treated with contempt. But Atlee steps into the last witness's place, and testifies to the fact that one hundredweight at a time was taken Can anything be more lamentable than such a perversion of truth? for either these men are asserting what they know to be contrary to fact, or two out of three of them are apparently ignorant of the most important details of their duties, and consequently totally unfit for the responsible situations they hold. If Atlee is right, what an additional burlesque have we here upon "the solemn commands of "the Legislature." Driving a coach and six through an Act of Parliament is fairly outdone where a hundredweight of gunpowder can so easily blow it to the winds. Will so clear a violation of the law as is here shown be permitted to pass unnoticed by the authorities? We elicit from the evidence the fact that although there exists no official inspector of gunpowder works, there are two persons depated to inspect and test the strength of the powder making for the Government. Their and improving the quality of iron. In 1728 a patent was granted to John Payne for machinery for obtaining motive power by We have heard it advanced as a non sequitur and boilers for applying heat; for improveatmospheric pressure; for improved furnaces to the suggestion that these mills should be ments in the manufacture of iron and salt. The removed farther from the presence of large improvements in the manufacture of iron are communities, that the communities came to the stated in the specification to consist in putting neighbourhood of the works and not the works certain ingredients into fusion with pig and to the communities. Now this is partly true and partly false. One set of mills may have vegetables, glass, salt, kelp, and pit-ash cinders sow iron, viz., the ashes of wood and other existed one hundred years, but we doubt from iron furnaces and forges, which ingredients whether the other two sets, some mile or two being so put into fusion or melted with pig, apart, have been established one-half that And in addition to this question of sow, or other brittle iron will make the like dates-if there really be anything in it--we change as charcoal does in the fire called the maintain that it is only within the last few finery in common forges, and will render the same into a state of malleability, as to bear the years that by the presence of steam and of stroke of the hammer, to draw it into bars or mills which are admitted to exist by Mr. Ashby, The specification further states that those or huge furnaces, and of the increased number of other forms at the pleasure of the workman. and which several tall shafts of modern construction fully identify, these works have be-gredients in a long hole, arch, or cavern, are to other bars being heated in the said melted income so formidable and alarming. If, in a word, we are thus far correct, there is not a habitation that has been built fifteen or twenty years, or even less, but what had a locus standi they now exist, and not an inhabitant of such prior to the formation of the bona fide works as dwellings but what would have a just cause for action if there be any virtue in the old notion novel nuisance. of the penalty attached to the formation of a THE ROYAL POLYTECHNIC. pass, between two large metal rollers (which have proper notches or furrows upon their surfaces), by the force of the engine thereafter described, or other powers, into such shapes or which was to cause the iron to pass through forms as shall be required. The engine force the rollers, consisted of a large vane wheel hung in a frame in the side of a building, the pressure of the in-current of air being directed upon the extremities of the vanes. It may be presumed to have been a sort of windmill, from which no beneficial result for the purpose proposed could be anticipated. This specification is deserving of notice, as suggesting the use of large metal rollers with notches or furrows on their surfaces for bringing the iron, drawn by the force of the hammer into bars, into the received shapes and forms; their use would be more analogous to the use of the old slitting rollers, than to the use according to the invention of Cort after the lapse of more than half-a-century. The furnaces to be employed, as described in Payne's specification, consisted of a series of "arched caverns," from and through which the fiery particles were to be conducted in succession by "flews" to heat the materials placed therein. From about this time attention would appear to have been directed to caverns as a substitute for the hollow fire and blast in the reduction of the pig or cast into malleable iron, and to the adoption of furnaces closely resembling the reverbatory furnace. In 1761 a patent was granted to John Wood for a "new way of making malleable iron from pig or sow metal, commonly called cast iron." The conversion, after certain preparatory operations, was to be performed in close vessels in an air furnace, by the aid of certain fluxes which, with the impurities from slag and the iron being brought into a tough and malleablestate is wrought into bars under the forge hammer. In the next year (A.D. 1762) a patent was granted to John Roebuck for "a way of making malleable iron from cast iron." The cast iron was to be melted in a hearth with a blast, that is, freed from substances interfering with malleability, then taken out of the fire, separated into pieces, and exposed to the action of a hollow pit-coal fire, heated by the blast of the bellows until reduced to a loop or ball of hot iron, which was to be drawn out under a forge hammer into bar iron. The specification of Roebuck proposes a combination of the hearth with a blast for the melting of the cast iron, and of the hollow pit-coal fire with the blast for the subsequent process of bringing the iron into a mass and state suitable for reduction into bar iron by the action of the forge hammer. The invention of Roebuck has recently been strangely confounded with the puddling process, the invention of Cort more than twenty years afterwards; the former invention was probably intended and may be regarded as an improvement on the well-known blooming process, which was performed by a blast in a hollow fire, whereas Cort's process, known as puddling, is performed without any blast in a reverberatory and the metal worked until reduced to nature, or air furnace. tramways between the Severn and different tion. Patents were granted in 1771 to John Cock- Such appears to be the state of invention and of speculation in this important branch of manufacture prior to and about the time of Cort's inventions; the labours of so many ingenious men, some of whom had opportunities of practising the different processes described in their specifications, must have materially advanced This was followed by a patent to John and the state of practical knowledge in the manuCharles Wood in the following year (A.D. 1763) facture of iron, particularly in the direction to for an invention, described in the specification which their labours were mainly directed, as an improvement on the former patent of namely, the manufacture of bar-iron from pitJohn Wood, two years before (A.D. 1761), for coal. The successful employment of pit-coal in "making cast iron malleable without charcoal the smelting furnace for the manufacture of or blast in an air furnace." The process de-cast-iron in the preceding century naturally led scribed is granulation and melting in close pots to its use and substitution for charcoal in the with a covering of clay, by which the iron be- subsequent process of the conversion of cast comes perfectly tough and malleable, and is to be into bar-iron; this may have been one cause of wrought under the hammer into half blooms. the reduction in 1740 of the number of furnaces This was followed by a patent to Thomas and using charcoal or wood fuel, inasmuch as those George Cranage (A.D. 1766), for "making pig having only a casual supply would probably be iron malleable in a reverberatory or air furnace abandoned by reason of the increased use of the with raw pit-coal only." The pig iron is to be pit-coal or mineral fuel, of which the supply was put into a reverberatory or air furnace, built of so abundant. proper construction, and without the addition of anything more than common raw pit-coal, and thereby converted into good malleable iron, and being taken red-hot from the reverberatory furnace to the forge hammer, is to be drawn into bars of various shapes and sizes, according to the will of the workman. The Cranages were in the employ of the Coalbrook Dale Company, then under the management of that eminent man Richard Reynolds, to whom, amongst other things, is due the credit of first employing iron instead of wood in the construction of rail or It is not improbable that the estimate given of the number of furnaces in the time of Lord Dudley is too high, and in 1740 is too low, and that allowing for the increased yield of furnaces working continuously with a constant supply of coal over those working intermittently with an uncertain supply, estimated at from 400 or 420 I am obliged to Mr. Norris for calling attention to an inaccurate statement in the preceding article, to the effect that the manufacture of iron with pit-coal at Coalbrook Dale had been attended with no great commercial success; that process appears to have been carried on continuously from its adoption in 1713. tons as compared with 60 or 70 tons per anm m, the suggested decrease in the quantity of iron made in the country in 1740 as compared with the quantity made in the time of Lord Dudley may not be accurate; calculations made by competent persons on this basis would lead to the conclusion that the quantity must have increased. However this may be, the quality of the iron was not good; the iron of British manufacture was used only for common purposes, and was not employed in the navy for purposes for which the quality was a material consideration; and in 1784 upwards of 75,000 tons of charcoal bar-iron was supplied from Sweden and Russia for consumption in the naval arsenals and other important works. It is highly probable that specimens of iron of a quality not greatly inferior if not equal to foreign marts were occasionally produced by the skill of British manufacturers working upon some of the suggestions of the many ingenious men who during the preceding century and a half had devoted themselves to a subject of such increasing national importance; the materials, the furnace, the hammers, the rollers, the blowing apparatus were in daily use, but the art whereby iron of a quality suitable for any purpose could be produced with certainty by the manipulation of the process whereby such a result was to sucthe unskilled artizan was strictly a mystery; ceed was not disclosed in any of the specifications and speculations interpreted by the light tions referred to, however near previous sugges of successful practice may now appear to have approached thereto. Such have been the characknowledge; the fragments, so to speak, of many teristics of all progress in every department of predecessors are, as it were, gathered up by some fortunate successor and combined into a system which as a whole constitutes, by the common consent of posterity, a landmark in the ocean of speculation, and an epoch in the history of the progress of each particular science. The labours of Henry Cort present such a landmark, and constitute such an epoch in the manufacture of British iron; the practice which he introduced, like the substitution of pit-coal, and the application of the more powerful blast, continues to the present day substantially the same as adopted at the foundry at Fontley, and published to the world in 1783 and 1784 by the specifications of the patents then obtained; the puddling, piling, faggotting, and heating, without the use of the blast and reduction of the iron by rollers, as practiced at Fontley, still survive and form part of the manufacture, whatever additions or alterations may have from time to time been introduced. MONEY-MAKING AT THE ROYAL MINT. THE marking-room by its name conveys no sort are in communication with another line of small subterranean shafting, driven by a 20-horse power engine. Shopkeepers and others, for the detection of guilty servants, have, ere now, marked pieces of gold and silver, but the marking pursued at the Mint is, we need not say, for a very different purpose. The "sized,"- -or as they might well be named after the judicial ordeal through which they have recently gone, assized blanks, are carefully weighed into this room, and then supplied to the attendant markers. A bag containing 720 oz., or 60 lb. troy of the golden above one of the machines, and a portion of them pieces is next emptied into a copper pan placed are made to fall into, and fill horizontally, or surface upon surface, a couple of feeding tubes. The machine is then started, and straightway the two pieces at the bottom of the tubes are made, by means of a couple of thin sliders, or miniature "shovels," as they are we believe technically called, to advance from beneath the tubes. The pieces are at the same time made to revolve-still in a horizontal position-between two grooved steel cheeks at a requisite distance from each other to administer a considerable amount of pressure to the circumference of the pieces, and, in fact, to raise a rim or protecting edge upon them at the expense of their diameters, which are thus lessened. The marked blanks, after this squeezing, are ejected by the action of the machine itself, and fall forward into a basket lined with pig-skin, and placed to catch them. In the return stroke of the sliders they carry two other pieces from beneath the tubes to the other end of the machine. where a similar amount of pressure is administered to them, and they are deposited in the basket below; this alternate motion is quickly repeated. The attendant has to take especial care that the pieces fall flatly into the tubes, and to keep up a constant supply, whilst a frequent testing of the work, produced by the aid of a steel gauge collar, is necessary also. The pieces must be made of aniform diameter, or as coin presently they would exhibit palpably the irregularity, and then be consigned to the melter, a "consummation" not to be wished at all, much less "devoutly." These machines are rapid in their movements, and 240 blanks per minute are consequently thrown into the basket from each. It must not be supposed that the milling on the edge is given in this way, or at this stage of the process of coining, as many persons imagine. That is, on the contrary, as will be shown, one of the last episodes in the gestative history of the sovereign, and all other milled coins struck at Tower Hill. The marking gives a plain rim only, and the object of this is to render it less necessary to put a very heavy strain on the dies afterwards in the coining press. The protecting edge of the future coin is in fact thus raised, and made ready to receive the ingraiting or beading from the obverse and reverse dies. As soon as one bag of the seeming shankless buttons have been properly "marked," they are returned with the ticket - daly numbered of their weight to their bag, and are ready for the following process. Of course, in describing the progress of one of these quantums, we have described that of the whole batch of gold of which we have been in pursuit, and it may simplify our subsequent revelations if to that one quantum we confine hereafter our attention. Leaving, then, our friend the marker to his monotonous duty, we follow the bag in question. The officer of the marking, annealing, and stamping branch again verifies, by weighing, the quantity received from the machine, and this Lime virtually counts them. He divides them into four parcels of 180 ozs. = 15 lbs. troy, or 701 pieces. These parcels are henceforth, when placed in smaller bags, denominated journies-from, as formerly explained, the French word journée, a day's work-and there is no doubt that in the days of the Norman rule in this kingdom, 701 erins were considered a very good day's work on the part of King William's minters. The four journies of gold are now carefully folded and placed in a butcher's tray, or a vehicle much resembling that dangerous article, and transferred to the annealing-room. Here there are eight He appliances. Into one of these sieves our friends gany ranging-tray. This has flutings in it, and We have thus seen that as there is a difficulty in making money outside the Mint, so is there some trouble in money-making within that wellguarded establishment. As a lady is said once to have remarked to an officer who had conducted her through its various departments, "Well! if it gives so much trouble to make a sovereign, I'm sure we ought not carelessly to spend it." The gold with which we set out from the refinery of Messrs. Brown and Wingrove has now been cast into bars, laminated, drawn, cut, weighed or assized-to coin a new word-marked, annealed or baked, pickled, bathed, and dried out for stamping, and in this stage of progress space warns us that till next week we must leave it. It is hoped, moreover, that thus far, at least, our readers have tracked us in our march through the Mint, and gathered much novel information from our teachings. THEORY OF NAVAL ARCHITECTURE. in our last article, page 259, last vol., we observe that Let these multiplications be performed for all the vertical columns, and the results inserted immediately under the respective ordinates, as shown in the table in large figures; in practice these results are written in red ink, by which means they are very readily distinguished from the ordinates. This being performed throughout the the results in each horizontal column, the sum columns, we readily see that if we add together when multiplied by one-third of the interval between the horizontal sections will give the For example, in transverse section 8 the sum of semi-area of the corresponding transverse section. 05, 58, 57, 15-4, 13.5, 39-6, and 10.0, equal to 90 05, multiplied by of 15, the common interval, or 5, gives 45-025 for the semi-area of that in the cullender, and again a douché bath of water is given them. By this time a change has come over the spirit of their dream. No longer dull and spiritless pieces of very suspicious-looking metal, they appear in their true colours-bright ovens, each with an iron door fitted with chains and beautiful. The most sceptical would not now and counterpoise weights; and there are in addi- doubt their being gold-the brass buttons have tion tables plated with iron, small carriages of apparently been doubly gilt while in the copper. the latter material, square shallow cast-iron pans They are, however, very wet after their repeated with shifting covers, open wrought-iron pans with-bathis, whilst it is necessary that, for stamping, oat covers, copper tubes, pot clay, and other they should be perfectly dry. Provision has been paraphernalia for the carrying out of the baking made for this difficulty. In the next apartment, business previously adverted to. The oven then, the drying-room, is a drying stove, a cast-iron open it may be imagined, is already heated by means of bed, about seven feet in length and four in width multiplied by their respective numbers in each a Jucke's patent furnace, and there is nothing at a guess-resting upon brickwork, and having a bat to supply it with the rich batch to be acted fire and flue beneath it. This is covered with beechupona. Well, the four journies are now once more wood sawdust-found to answer the purpose miled, and they are placed this time in a maho-best-and has upon it sieves and other such like section. These sums of the results of the ordinates The figures in the horizontal columus give respectively the ordinates for the transverse sections; and those in the vertical columns the ordinates for the horizontal sections. respectively. and the sum of the results, 1832-0, horizontal column are placed to the right in the in the column. To obtain the displacement from the column headed" areas," these areas, or areas divided by a constant number, might, as we have before stated, be represented by the ordinates of a curve, the line of abscissæ being the middle line of the half-breadth plan, and the ordinates placed at the respective transverse sections, the areas of which they represent. The two results should therefore in all cases be water-line. tire curvilinear area is equal to = m 12 3 The area of the figure thus formed will represent at the constructed load water-line, and their manner:· of the keel; at these heights lines are drawn per- Rule. To find the curvilinear area between two equidistant ordinates, such as of the shaded pordistant ordinates. Multiply the outside ordinate tion of Fig. 15, in terms of three consecutive equi and the middle ordinate by 8, add the results adjacent to the shaded portion of the figure by 5, together, and subtract the other extreme ordinate from the sum; the remainder multiplied by onetwelfth of the distance between the ordinates, will give the area required. 3.6, 55-2, 103.95, 141-5, 171-4, 209-7,and 236-95, We have already shown that the quantities or the sums of the vertical columns of large of the several horizontal sections divided by figures in the table page 299, are the areas acertain number; in order, therefore, to find This multiplied by 2 for both sides gives 76944, the displacement in cubic feet for both sides from the L. W. line to upper part of the keel. Were there any portions of the ship outside the extreme sections, these should be calculated by the ordinary rules of mensuration, and added to the above result to give the total displacement. In the present example the only portions situated outside of the extreme sections, are the thin iron found for any draught of water when the plane of which is 459 6, and subtract 103.95 from it, keel and the rudder and post, all of which may be safely neglected as inappreciable. The cubic feet divided by 35-the number of cubic feet of sea water in one ton-gives 219-84 as the total dis placement in tons to the load water-line. To obtain the displacement by "horizontal sections," the ordinates in each horizontal column are multiplied by the number opposite to it in the second vertical column from the left; and the results placed immediately to the right of the ordinates, written in red ink, and as is shown in the table in large figures. Thus :-The ordinates in the horizontal column 1 are multiplied by, those in column 14 by 2; and so forth for all the horizontal columns. line. In order, however, to find the displacement P, N, When these are completed, the results will form a series of vertical columns; and it will be seen that the ordinates corresponding to any horizontal section, will have been multiplied respectively by In our investigations on page 104 we obtained the numbers opposite to them in the second ver- by the summation of a large number (2n) of very tical column from the left; the sum, therefore, of small trapeziums, the area of the entire figure the results in the vertical columns, when multi-between P, N, and P, N.; but it is clear that we plied by one-third the interval between the vertical sections, give respectively the semi-area of the corresponding horizontal sections. Thus, the sum of these quantities in the vertical column headed L. W. L., or the sum of 05, 18, 19, 5'8, 60, &c., 38, 40, and 05, altogether equal to 236-95, when multiplied by 4.2 will give the semi area of the load water-section. These sums for the several horizontal sections, inserted at the foot of the respective columns, are 36, 55.2, 103.95, 141-5, 171-4, 209-7, and 236.95, and to proceed as before, instead of multiplying each of these quantities by 4.2 to obtain the semiarea of the sections, we shall regard them as the ordinates of a curve, the line of abscissæ of which is the middle line of the body plan, and the positions of these ordinates, the intersections of this line by the horizontal sections. These quantities must, therefore, be multiplied by the numbers standing at the head of the vertical columns, viz., by, 2, 1, 2, 14, 4, and 1 the displacement to the 4 W.L. we have only to multiply 3-6 by 5, 55-2 by 8, the sum of multiplied by one-twelfth of the distance (1-5 ft.) leaving 355-65 as a remainder; this quantity between the horizontal sections, and one-third the distance between the vertical sections, gives 186-7162 for the displacement in cubic feet to the 44 W.L., and the corresponding number of tons is 5.3347. To obtain the displacement to the 4 W.L., 3.6, 55.2, and 103.95 are regarded as the ordinates to a curve, and multiplied by, 2, and respectively, and then multiplying by the proper proportion of the distances between the horizontal and vertical sections, the displacement in cubic feet is found to be 689-535, and in tons 19-701. The whole of which calculations will be readily made out from the table. In obtaining the displacement to the 3 W.L. the ordinates 36, 55.2, 103.95, and 141-5, are multiplied by 1, 3, 3, and 1 respectively, in accordance with the third rule for finding a curvilinear area; the sum of which results or 622.55 when multiplied by the proper proportions of the distance between the horizontal and vertical sections, will give 1470-7743 for the number of cubic feet displacement to that Line equal to 42-0221 tons. To find the displacement to the 3rd W.L. The displacement between the L.W.L. and 3 W.L. is found by multiplying 236.95 by 1, 2097 by 4, and 1714 by 1, and adding the results together, giving 1247-15; then multiplying in the usual manner, there results 5238-03, which is the number of cubic feet displacement between the L.W.L. and the 3 W.L., and the number of tons in the same is 149-658; this number subtracted from the total displacement, 219-84, leaves 70-182 for the displacement to the 3 W.L. The same result would be obtained by making the quantities 3-6, 55.2, 103-95, 141-5, and 171-4, the five equidistant ordinates of a curve, and finding the curvilinear area in the usual way. The displacement between the L.W.L. and the 2 W.L. is obtained in the same way as that between the upper part of keel and the 44 W.L.viz., by multiplying 236-95 by 5, 2097 by 8, add |