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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 lato 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 sone 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 to do with the failure of the process in those cases columns.

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 dle: homogeneous malleable metal which may be favour of the Bessemer iron. For the accuracy of carbonised, and the silicum be removel, 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 resulteel from steel tested in the proving machine at Woolwich the iron, instead of running direct from thio the presence of a like quantity of phosphorus; it, therefore, became necessary to remove those 'sub: Arsenal bore, according to the reports of Colo- melting furnace into the mould must first be stances. 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 moro 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 chietly of silicatos 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 with the fluid metal, during the process, and the lished experiments of Mr. Fairbairn, Stafford- tough metal, of from 5 to 10 tons in weight, can lbs. to 73,100 lbs. ; while according to the pub- ordinary manner.

Conical masses of this pure
quantity of phosphorus was thereby reduced. Thus
many months were consumel in laborious and expen- shire plates bear only a mean strain of 45,000 be produced at Woolwich at a cost not exceed-
sive experiments; consecutive steps in advance were lbs., and Low Moor and Bowling plates a meaning £6 12s. per ton, inclusive of the cost of
made, and many valuable facts were clicited.” of 57,120 lbs. per square inch. There is also pig iron, carriage, remelting, waste in the pro-

Here we are sneeringly told that neither of another fact of great importance, as we are re- cess, labour, and engine-power. These impor-
the 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 Eard-
that 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 EXPLOSIONS AT GUNPOWDER
to the MECHANICS' MAGAZINE of September 13, at the Institution by Mr. Bessemer, and from

WORKS. 1856, by Mr. William Truran, the author of an

which the sample plates were made, it was less It is desirable, we think, before the memory admirable volume on "The Iron Manufacture troublesome, less expensive, and less wasteful of the late fatal explosions at Hounslow passes of Great Britain ;” and in that article the of material, to make plates weighing from 10 to entirely from the public mind, to recur once author distinctly pointed out the fact that Mr. 20 cuts. than to produce smaller ones ; and, more to certain important considerations sugBessemer's process did nothing towards the re

indeed, there was but little doubt that large gested by them. In doing this we will, in the moval of the sulphur and phosphorus from the plates would eventually be made in preference, first place, revert to the evidence given before metal. Mr. Bessemer committed a great

and that those who wanted small plates would the Coroner in reference to the late inquiry, mistake,” said Mr. Truran, “when he claimed have to cut them from the large ones. A

confining ourselves to the last sitting of the " for his plan the production of that quality moment's reflection therefore shows the great jury. The following are extracts from that “known as charcoal iron, simply from the re

economy of the new process in this respect ; evidence : fining being conducted without contact with and when it is remembered that every riveted

“Mr. Rowse stated that he was about 90 yards off “mineral fuel. A superficial acquaintance with joint in a plate reduces the ultimate strength at the time. It was the lower press exploded first. “ the subject would have shown that the quality of each 100 lbs. to 70 lbs., the great value of Could not say whether the treble dust was brought of the fuel used in the manufacture of a

long plates for girders and for ship-building into the press-house over night, or whether more in moiety of the bar-iron, so far as regards the will be fully appreciated.

the morning was taken in a boat; could not say how “usual contaminating ingredients, sulphur and Nor.can we leave this subject without re

much there was on the premises the day before. The phosphorus, has nothing to do with the ulti-ferring, at the risk of repetition, to the wonderful | The powder was pressed enough. Takes about five

pressure is taken off by letting the water off directly. “mate quality of the bir.” And again the promises which the Bessemer process holds out minutes to move the powder from the press. Cannot same gentleman, in an article which appeared in to us in reference to the manufacture of ord- remember how much in the press-house the night the MECHANICS' MAGAZINE of the following nance. Many attempts have been made to before. Might have been fifty barrels. Could not month, said :-“It is questionable if one single produce wrought-iron ordnance, and this object week on the premises.

state there was not eight hundred barrels made per "aton of phosphorus or sulphur was separated has been successfully accomplished in the case “Mr. Ashby, the manager of the works: Had not " [in Mr. Bessemer's experiments], for the re- the large gun produced at the Mersey forge. any further information to give as to the cause of the “sults of analysis are altogether against a more But, however perfect this one gun may be, the accident. Was now constructing the press in a very « favourable conclusion. Phosphorus and sul- time required to make it, and its immense cost, with 20 feet of earth over. This wall or fence to bo

different manner with transverse arches, bomb-proof, phur exist to the extent of 1} per cent. in manifestly renderit still, as Mr. Bessemer stated, between the press-house and the place where the men many pig-irons, and their removal is essentially a great desideratum to produce guns rapidly and would work the pumps for the hydraulic pressure.

necessary to the production of good malleable cheaply, of a material equal to, or greater in ten- The new press to carry cight barrels instead of double iron.” How Mr. Bessemer could have gone on sile strength than wrought iron, and, if possible, that quantity, as was the case in the late press. pottering at chemical analyses in order to disco- free from the liability which that material has There was a Government inspection by two military ver facts which a sound practical iron-maker to flaws and to deterioration during long expo- for Government contracts. The firm had existed 33

officers to ascertain the quality of the powder making was thus clearly placing before him, or how he sure to a welding heat. It is believed that the years. The mills had been in existence one hundred can now have the effrontery to sneer at those Bessemer process supplies this desideratum, as years. Should not have a water-tank over the new who were taking pains to teach him what he masses of cast malleable metal can be produced press-house. Considered it caused the great lateral was so manifestly ignorant of, we are at a loss of ten or twenty tons in weight in a single piece, explosion, It was his decided opinion explosions and two or three such pieces may be conve

were unavoidable. to conceive.

Had increased the number of

mills on the premises by five in the last fifteen years. But while we may look to Mr. Bessemer in niently made by the same apparatus in one

Had sworn that 400 barrels on an average was the in vain, we fear, for any manly recognition of day. The metal so made may be either soft quantity made on the premises at Twickenham per his own shortcomings

, or any grateful acknow- malleable iron, or soft steel. In order to prove week. Kad no reason from subsequent inquiry of ledgement of the aid which others offered m, the extreme toughness such iron, and the other means to alter that statement. Would not and while we must receive with caution all that strain to which it may be subjected without swear there was not eight hundred barrels per week he comes forward to say in commendation of his bursting, several cast and hammered cylinders exploded after the press-house, there were three men

made on the premises. In the corning-house, which own proceedings, we have no wish to deny that were placed cold under the steam hammer, and employed. The quantity of powder usually there was he has at last done good service to the iron ma- crushed without the least tearing of the metal. from ten to fourteen barrels. In the green charge,

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or what was now called incorporating houses, forty | offices must be a sinecure-perhaps placed under | occurred in January last to the spiral staircase twy pounds of powder only at a time; forty pounds some comfortable arrangement which makes has effectually crippled, as we lately intimated, being allowed by Act of Parliament, and two pounds“ things right”-or we should not have had to the resources of the directors. The costly lititwenty barrels at a time. One-third of the powder allude to the contumely with which a Govern- gation of actions on the part of some of the sufglazed at Twickenham works came from tho Bedford ment Inspector was treated upon demanding ferers, and the liberal discharge of a fair and Mills.

admittance at the gates of the works the day humane consideration of the claims of others, “ Henry Atlee: Is a glazing man. Had been after the late accident, and whose person was have exhausted the means at the disposal of the much injured. There were one hundred barrels of not even known to the man who had held the directors, and nothing remains but the sale of sometimes there are as many as three or four hundred post of porter for many years.

the premises and their really valuable contents baiTels, sometimes only twenty. On the day before Mr. Ashby's statement that the proprietors by public auction. This effort having failed, the esplosion he was in the press-house ; saw two of the works had determined upon construct- the Institution must be sacrificed, unless another hundred barrels there. Forty-nine barrels had been ing the press in a different manner to carry company can be formed to save it from destrucduring the morning previous to the explosione allad eight instead of sixteen barrels, is a tacit ad- tion. This, notwithstanding the information no instructions as to quantity of powder to be in the mission that his own judgment is at variance which we lately published upon this subject, glazing-house at once. Glazed one hundred and with that of his employers. We are still dis- has not, it now appears, been accomplished. It thirty barrels a day in both houses. Three men posed to think that even the raising of the would be a lasting discredit alike to the scientific employed. Sometimes glazed more, sometimes less. iound “ upon transverse arches and rendering taste and moral tone of London if such an InThat was the quantity expected to be done. Worked "it bomb-proof” will not afford sufficient pro- stitution should be suffered to cease for want of on Sundays as on other days. Quantity of powder tection for the men, unless the conditions of the few thousand pounds which would at once was a hundred-weight at a time. Should return to the Act of Parliament and the presumed regula- reinstate it in its position among the unobjecthe mills when sufficiently recovered."

tions as to the prescribed quantity of powder tionable and popular Lions of the Metropolis. We make no reference here to the evidence to be admitted under the roof at one time be On public grounds we venture to press the of Mr. Taylor, the former engineer to the works, cessarily gunpowder proof. "Mr. Ashby's " de mediate consideration of public philanthropists.

case of the Polytechnic upon the serious and im“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- attempts to mitigate or suppress these calami- with the design of the Institution, unless the pear to us to agree with that rendered by him ties; and in the very front of so bold and scientific and religious public interpose their cobefore 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 largest firms for the manufacture of gunpowder

our own columns the testimony of one of the reproducing a remark openly made in court,

THE CASE OF HENRY CORT, that “Mr. Taylor's evidence would appear to in the world, where, as a consequence of judi" have been more valuable out of doors than cious forethought, and the adoption of very HIS INVENTIONS IN THE MANUFACTURE "in." It may appear strange that the im ‘ many improvements,” a fatal accident has not

OF BRITISH IRON. 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 THOMAS WEBSTER, M.A., F. R.s., &c., Barrister-at-Law. appeared in most of the daily and other jour conventional term now applied to working men The specifications recently published by Mr. nals. Our notes were, however, taken by an

No. IV.

that one hundredweight at a time was taken maintain that it is only within the last few / finery in common forges, and will render the “the Legislature.” Driving a coach and six prior to the formation of the bona fide works as forms as shall be required. The engine force bave we here upon “the solemn commands of years, or even less, but what had a locus standi scribed, or other powers, into such shapes or

-is not confined to gunpowder works ; but Woodcroft, under the authority of the Commisespecial hand, and we have great reason to contide in their integrity and truthfulness.

happily it does not, through the merciful in- sioners of Patents, show that the inventive It will have been already observed that while extent as it did a few years ago. Perhaps the during the first half of the 18th century, to the

terference of the Legislature, exist to the same genius of the country wa directed principally, Rowse could not swear there were not 800 Government will ere long see in the manufac- addition of materials and ingredients, and the barrels made per week, Ashby states there were

ture of gunpowder a reason for some change ; and adoption of fluxes for facilitating the melting bnt 400, but would not say there were not 800, as the conditions of one of its Acts has already and improving the quality of iron. and Atlee gives the quantity glazed as 130 been grossly violated, it needs no extraordi

In 1728 a patent was granted to John Payne on upon Sunday, to 910 barrels per week ! Mr. nary: excuse for an immediate and searching for machinery for obtaining motive power by Ashby further states that the greatest quantity We have heard it advanced as a non sequitur and boilers for applying heat ; for improve

atmospheric pressure ; for improved furnaces kept in the corning-house was from ten to to the suggestion that these mills should be ments in the manufacture of iron and salt. The fourteen barrels. Atlee tells us that forty-nine removed further from the presence of large improvements in the manufacture of iron are barrels had been moved to the glazing-house communities, that the communities came to the stated in the specification to consist in putting from the coming-house during the morning of neighbourhood of the works and not the works certain ingredients into fusion with pig and the explosion. Mr. Ashby further states to the communities. Now this is partly true lowed in the incorporating-houses, according existed one hundred years, but we doubt from iron furnaces and forges, which ingredients that forty-two pounds was the quantity al- and partly false. One set of mills may have sow iron, viz., the ashes of wood and other to Act of Parliament, and we are left for the whether the other two sets, some mile or two being so put into fusion or melted with pig, moment to infer that the Act has not been treated with contempt. But Atlee steps into apart, have been established one-half that the last witness's place, and testifies to the fact time. And in addition to this question of sow, or other brittle iron will make the like

change as charcoal does in the fire called the

if really be in into the incorporating-houses !

same into a state of malleability, as to bear the Can anything be more lamentable than such years that by the presence of steam and of stroke

of the hammer, to draw”it into bars or huge furnaces, and of the increased number of other forms at the pleasure of the workman. a perversion of truth ? for either these men are mills which are admitted to exist by Mr. Ashby, The specification further states that those or az erting what they know to be contrary and which several tall shafts of modern con other bars being heated in the said melted into fact, or two out of three of them are struction fully identify, these works have be- gredients in a long hole, arch, or cavern, are to apparently ignorant of the most important dewils of their duties, and consequently totally word, we are thus far correct, there is not a have proper notches or furrows upon their surcome so formidable and alarming. If, in a

pass, between two large metal rollers (which unfit for the responsible situations they hold. habitation that has been built fifteen or twenty faces), by the force of the engine thereafter deIf Atlee is right, what an additional burlesque

they now exist, and not an inhabitant of such which was to cause the iron to pass through through an Act of Parliament is fairly outdone dwellings but what would have a just cause for the rollers, consisted of a large vane wheel hung where a hundredweight of gunpowder can so action if there be any virtue in the old notion in a frame in the side of a building, the pressure easily blow it to the winds. Will so clear a violation of the law as is here shown be

of the penalty attached to the formation of a per

of the in-current of air being directed upon the novel nuisance. mitted to pass unnoticed by the authorities?

extremities of the vanes. may be presumed We elicit from the evidence the fact that

to have been a sort of windmill, from which no although there exista no official inspector of

THE ROYAL POLYTECHNIC.

beneficial result for the purpose proposed could ganpowder works, there are two persons de- It is with the deepest regret we learn the im- be anticipated. This specification is deserving pated to inspect and test the strength of the pending close of the above popular Institution. of notice, as suggesting the use of large metal powder making for the Government. Their . The expenses connected with the accident which I rollers with notches or furrows on their surfaces

for bringing the iron, drawn by the force of the tramways between the Severn and different tons as compared with 60 or 70 tons per annum, hammer into bars, into the received shapes and parts of the works. The manufacture of mal- the suggested decrease in the quantity of iron forms ; their use would be more analogous to leable from cast iron with pit-coal had been made in the country in 1740 as compared with the use of the old slitting rollers, than to the carried on for upwards of half-a-century* since the quantity made in the time of Lord Dudley use according to the invention of Cort after the its introduction in 1713, under the super- may not be accurate ; calculations made by lapse of more than half-a-century.

intendence of Abraham Darby at Coalbrook competent persons on this basis would lead to The furnaces to be employed, as described in Dale, and technically termed the “ buzzing the conclusion that the quantity must have Payne's specification, consisted of a series of process," was the last of the series of inventions increased. “arched caverns,” from and through which the the subject of letters patent for the conversion However this may be, the quality of the iron fiery particles were to be conducted in success of cast into malleable iron by pit-coal, prior to was not good ; the iron of British manufacture sion by "flews” to heat the materials placed the puddling process of Cort, eighteen years was used only for common purposes, and was therein. From about this time attention would afterwards, towards which, the use of the rever not employed in the navy for purposes for appear to have been directed to caverns as a beratory furnace was a step in the right direc- which the quality was a material consideration ; substitute for the hollow fire and blast in the tion.

and in 1784 upwards of 75,000 tons of charcoal reduction of the pig or cast into malleable iron, Patents were granted in 1771 to John Cock-bar-iron was supplied from Sweden and Russia and to the adoption of furnaces closely resem- shutt, for making malleable iron directly from for consumption in the naval arsenals and other bling the reverbatory furnace.

the ore in a finery or bloomery,” for "refining important works. It is highly probable that · In 1761 a patent was granted to John Wood pig iron with charcoal into wrought iron," and specimens of iron of a quality not greatly infor a “new way of making malleable iron from for a new finery or bloomery,” the invention ferior if'not equal to foreign marts were occapig or sow metal, commonly called cast iron.” consisting mainly in charging and heating of sionally produced by the skill of British manuThe conversion, after certain preparatory opera- the finery, and in the greater supply of air to facturers working upon some of the suggestions tions, was to be performed in close vessels in the metal than in the common way. In 1783 of the many ingenious men who during the prean air furnace, by the aid of certain fluxes (three months after the first of Cort's patents), ceding century and a half had devoted themwhich, with the impurities from slag and the patent was granted to Peter Onions, for selves to a subject of such increasing national iron boing brought into a tough and malleablestate “working and refining cast iron, and convert-importance; the materials, the furnace, the is wrought into bars under the forge hammer.

ing the same from a fluid state into wrought hammers, the rollers, the blowing apparatus In the next year (A.D. 1762) a patent was

or bar iron,” by running the cast iron direct were in daily use, but the art whereby iron of a granted to John Roebuck for “a way of making from the smelting into another furnace, in which quality suitable for any purpose could be promalleable iron from cast iron." The cast iron it was subjected to a blast and fire until the duced with certainty by the manipulation of was to be melted in a hearth with a blast, metal became less fluid, and thickened into a the unskilled artizan was strictly a mystery ; and the metal worked until reduced to nature, kind of paste, when it was stirred and again the process whereby such a result was to sucthat is, freed from substances interfering with subjected to the blast, the operation of stirring ceed was not disclosed in any of the specificamalleability, then taken out of the fire, sepa- being continued until the scoria separate and tions referred to, however near previous sugresrated into pieces, and exposed to the action of the particles of iron cohere, when the workman tions and speculations interpreted by the light a hollow pit-coal fire, heated by the blast of the collects and gathers them into a lump, and of successful practice may now appear to have apbellows until reduced to a loop or ball of hot after being re-heated to a white heat is taken proached thereto. Such have been the characiron, which was to be drawn out under a forge. The treatment of the iron in this second furnace knowledge ; the fragments, so to speak, of many

to the hammer, and forged into malleable iron. teristics of all progress in every department of hammer into bar iron. The specification of Roebuck proposes a combination of the hearth has been supposed to be a near approach to the predecesso with a blast for the melting of the cast iron, and puddling of Cort, but they differ in the material some fortunate successor and combined into a of the hollow pit-coal fire with the blast for the particular of the use of a powerful blast as in system which as a whole constitutes, by the subsequent process of bringing the iron into a the ordinary finery, which was a wasteful and common consent of posterity, a landmark in the mass and state suitable for reduction into bar iron extravagant system, whereas in Cort's system ocean of speculation, and an epoch in the history by the action of the forge hammer. The inven-no blast whatever was used, but the process of the progress of each particular science. The tion of Roebuck has recently been strangely without requiring any

blast by bellows, or cy- and constitute such an epoch in the manufacture

was to be completed, as will hereafter appear, labours of Henry Cort present such a landmark, confounded with the puddling process, the invention of Cort more than twenty years

after-
linder, or otherwise.

of British iron ; the practice which he introwards ; the former invention was probably in Such appears to be the state of invention and duced, like the substitution of pit-coal, and the tended and may be regarded as an improve- of speculation in this important branch of manu- application of the more powerful blast, conment on the well-known blooming process, which facture prior to and about the time of Cort's in- | tinues to the present day substantially the was performed by a blast in a hollow fire, ventions ; the labours of so many ingenious same as adopted at the foundry at Fontley, and whereas Cort's process, known as puddling, is men, some of whom had opportunities of prac- published to the world in 1783 and 1784 by performed without any blast in a reverberatory tising the different processes described in their the specifications of the patents then obtained"; or air furnace.

specifications, must have materially advanced the puddling, piling, faggotting, and heating, This was followed by a patent to John and the state of practical knowledge in the manu- without the use of the blast and reduction of Charles Wood in the following year (A.D. 1763) facture of iron, particularly in the direction to the iron by rollers, as practiced at Fontley, still for an invention, described in the specification which their labours were mainly directed, survive and form part of the manufacture, as an improvement on the former patent of namely, the manufacture of bar-iron from pit- whatever additions or alterations may have John Wood, two years before (A.D. 1761), for coal. The successful employment of pit-coal in from time to time been introduced. "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

MONEY-MAKING AT THE ROYAL MINT. 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 Tue marking-room by its name conveys no sort wrought under the hammer into half blooms. the reduction in 1740 of the number of furnaces it. These operations are, nevertheless, of much This was followed by a patent to Thomas and using charcoal or wood fuel, inasmuch as those importance to the artistic finish of the coins to George Cranage (A.D. 1766), for “ making pig having only a casual supply would probably be be produced. It contains eight marking machines iron malleable in a reverberatory or air furnace abandoned by reason of the increased use of the mounted on strong muhogany frames, and set in with raw pit-coal only." The pig iron is to be pit-coal or mineral fuel, of which the supply was motion by straps running over pulleys, and which put into a reverberatory or air furnace, built of so abundant.

are in communication with another line of small proper construction, and without the addition It is not improbable that the estimate given subterranean shafting, driven by a 20 horse power of anything more than common raw pit-coal, of the number of furnaces in the time of Lord engine. Shopkeepers and others, for the detection and thereby converted into good malleable iron, Dudley is too high, and in 1740 is too low, and of guilty servants

, have, ere now, marked pieces of and being taken red-hot from the reverberatory that allowing for the increased yield of furnaces gold and silver, but the marking pursued at the furnace to the forge hammer, is to be drawn working continuously with a constant supply of Mint is, we need not say, for a very different pur

pose. The “sized,”--or as they might well be into bars of various shapes and sizes, according uncertain supply, estimated at from 400 or 420 named after the judicial ordeal, through which

will . in the employ of the Coalbrook Dale Company,

fully weighed into this room, and then supthen under the management of that eminent inaccurate statement in the prcceding article, to the effect plied to the attendant markers.

A bag conman Richard Reynolds, to whom, amongst other that the manufacture of iron with pit-coal at Coalbrook taining 720 oz., or 60 lb. troy of the golden things, is due the credit of first employing iron instead of wood in the construction of rail or I from its adoption in 1713. that process appears to have been carried on continuously picces is next emptied into a copper pan placed

above one of the machines, and a portion of them

No. IV.

* I am obliged to Mr. Norris for calling attention to an

are made to fall into, and fill horizontally, or sur. gany ranging-tray. This has Autings in it, and appliances. Into one of these sieves our friends face upon surface, a couple of feeding tubes. The when shaken the blanks naturally range them are placed when removed from the bath, and by machine is then started, and straightway the selves on their edgas in the flutings, and thus friction with the heated sawdust, the workman in two pieces at the bottom of the tubes are made, render it easy for the worker to take up rouleau charge of the stove soon gets rid of the moisture by means of a couple of thin sliders, or miniature after rouleau of them for deposition in the anneal. upon their faces. He is not, however, satisfied "shovels," as they are we believe technically called, ing-box. This becomes useful next, and it is of with this. There may be particles of dust adhering to advance froin beneath the tubes. The pieces just sufficient dimensions to receive on their edges, to them, and these must be got rid of. He are at the same time made to revolve-still in a and confortably—that is, without pressing them has at hand a muffle--a kind of coffee roasthorizontal position-between two grooved steel into it—the 2,804 will be sovereigns. If this ing apparatus made of copper, perforated with cheeks at a requisite distance from each other to rectangular box were too small, the expansion of small holes, and which can be inade to revolvo administer a considerable amount of pressure to the gold pieces by heating would inevitably cause within hollow heated cylinder of iron. the circumference of the pieces, and, in fact, to it to fly assunder. Therefore it is that rooin Into this “muffle" he next places the sinooth raise a rim or protecting edge upon them at the must be given to allow for their increased bulk. and healthy-looking pieces, and here their expense of their diameters, which are thus les. The 2,804 hard pieces of gold — become hard "drying-out” is soon made complete. Again the sened. The marked blanks, after this squeezing, by compression in the laminating and drawing officer receives them at the scales, divides the are ejected by the action of the machine itself, operations-safely ensconsed in their bod, are 2804 into the four packets of 701—the journey and fall forward into a basket lined with pig-skin, covered with thick wrought-iron tops, “ to weight notes on the ticket the working loss in and placed to catch them. In the return stroke make assurance doubly sure” that no air shall the various operations, if any there haply beof the sliders they carry two other pieces from oxidize their surfaces, nor cause volatilization, has them replaced in the butcher's tray, and beneath the tubes to the other end of the machine, and with pot clay the joints are plastered over. despatches them to the room in which they are to wbere a similar amount of pressure is administered A carriage mounted on small wheels is in waiting receive finally the stamp of approbation-the to them, and they are deposited in the basket at the oven's inouth to receive the rich freight; portrait and the superscription of our gracious below; this alternate motion is quickly repeated. it does receive it speedily by use of block and fall, Queen—and to become sovereigns theinselves. The attendant has to take especial care that the and then the whole is backed into the oven, form Silver and copper blanks undergo processes after pieces fall flatly into the tubes

, and to keep up a ing thus a more expensive pie than poor Soyer or pickling analogous to those described, the silver constant supply, whilst a frequent testing of the Mrs. Smith ever dreamt of. One hour suffices for becoming in appearance "frosted,” and the copper work, produced by the aid of a steel gauge collar, the cooking; the box and its contents are brought of a bright salmon colour. Six workmen perform is necessary also. The pieces must be made of to a cherry-red heat, allowed for a short time—a the whole of the duties of the marking, annealing, uniform diameter, or as coin presently they would few minutes—to remain so, and then withdrawn. blanching, and drying-rooms. exhibit palpably the irregularity, and then be The box, removed from its carriage (which awaits, We have thus seen that as there is a difficulty consigned to the melter, a "consummation” not to and speedily receives another pie) is placed in making money outside the Mint, so is there be wished at all, much less “ devoutly." These upon the stone floor to cool. While waiting some trouble in money-making within that well. uachines are rapid in their movements, and 240 for its cooling, our readers may be told guarded establishment. As a lady is said once to blauks per minute are consequently thrown into that in the case of silver being operated upon have remarked to an officer who had conducted the basket from each. It must not be supposed in this department, the open pans or boxes her through its various departments, “Well! if that the milling on the edge is given in this way, are used, that metal requiring a different mode of it gives so much trouble to make a sovereign, I'm or at this stage of the process of coining, as treatment, and the time for annealing it being much sure we ought not carelessly to spend it.” The many persons imagine.

That is, on the con shorter than that for gold. As regards copper, gold with which we set out from the refinery of trary, as will be shown, one of the last episodes that is baked in copper cylindrical boxes, made Messrs. Brown and Wingrove has now been cast in the gestative history of the sovereign, air-tight, brought to a red heat, and plunged im into bars, laminated, drawn, cut, weighed or and all other milled coins struck at Tower Hill

. mediately into cold water. In each case the metal assized—to coin a new word-marked, annealed The marking, gives a plain rim only, and the is softened sufficiently for coining. It is now time, or baked, pickled, bathed, and dried out for object of this is to render it less necessary to put however, to remove the crust of our pie. The lids of stamping, and in this stage of progress space a very heavy strain on the dies afterwards in the the box are accordingly taken off, and it is in. warns us that till next week we must leave it. coining press. The protecting edge of the future verted over a copper dish or tray, which receives It is hoped, moreover, that thus far, at least, our coin is in fact thus raised, and made ready to re the contents. A workinan catches this up, carries readers have tracked us in our march through ceive the ingraiting or beading from the obverse it to a cistern, and transfers the golden discs to a the Miut, and gathered much novel information and reverse dies. As soon as one bag of the cullender resting beneath a water-tap. A forcible from our teachings. seeming shankless buttons have been properly douché bath is now administered to them, and they "marked," they are returned with the ticket are thus freed from all foreign matter. But another

THEORY OF NAVAL ARCHITECTUKE. - daly numbered — of their weight to their process awaits them—they must be also pickled; heg, and are ready for the following process. for although fire and water have done much to Of course, in describing the progress of one of th:cse purify them externally, they are not yet sufficiently CONTINUING our explanation of the table given batch of gold of which we have been in pursuit, maesty. A cast-iron copper-if we may be per- respective compartments, the table may be looked quantums, we have described that of the whole brighit to become honoured with the impress of in our last article, page 299, last vol., we observe that

after the ordinates have been inserted in their and it may simplify our subsequent revelations ifmitted to use an Irishism-lined with lead, and con. to that one quantum we confine hereafter our taining a boiling but weak solution of sulphuric upon as a map on which the elevation of the attention. Leaving, then, our friend the marker acid, awaits in the blanching-room the coming of surface is registered from a fixed level. We now to his monotonous duty, we follow the bag in the candidates for sovereignty. They are speedily will obtain the displacement by “vertical secquestion. The officer of the marking, annealing, deposited therein, and a workman by aid of an and stamping branch again verifies, by weighing, ashen pole stirs them so that each individual tions.” Every ordinate is first multiplied by the the quantity received from the machine, and this blank is brought to face the acid. This pickling vertical column, thus: all ordinates in the first

number standing at the head of its respective Lime virtually counts them. He divides them affair is the work of a few minutes only in the into four parcels of 180 ozs.=15 lbs. troy, or 701 case of gold and silver, which latter requires a

column, headed keel or 5 W.L., is multiplied by pieces. These parcels are henceforth, when placed stronger

solution of sulphuric acid than its richer , those in the second column headed 4! W. L. is in smaller bags, denominated journies-froin, as neighbour; whilst plebian copper

blanks demand multiplied by 2, and so on for the others. formerly explained, the French word journèe, a some hours of rest in a cold mixture of acid and

Let these multiplications be performed for all dars of the Norman rule in this kingdom, 701 fore provided for the indulgence of the last-named. shown in the table in large figures ; in practice day's work-and there is no doubt that in the water. A number of pickling troughs are there the vertical columns, and the results inserted

immediately under the respective ordinates, as ezens were considered a very good day's work on The pickled blanks of gold are now removed these results are written in red ink, by which the part of King William's minters.

in the collender, and again a douché bath of water The four journies of gold are now carefully folded is given them. By this time a change has come

means they are very readily distinguished from the and placed in a butcher's tray, or a vehicle much over the spirit of their dream. No longer dull ordinates. This being performed throughout the resembling that dangerous article, and transferred and spiritless pieces of very suspicions-looking columns, we readily see that if we add together to the annealing-room. Here there are eight metal, they appear in their true colours-bright when multiplied by one-third of the interval ovens, each with an iron door fitted with chains and beautiful. The most sceptical would not now and coanterpoise weights; and there are in addi- doubt their being gold—the brass bottons have semi-area of the corresponding transverse section.

between the horizontal sections will give the tion tables plated with iron, small carriages of apparently been doubly gilt while in the copper; For example, in transverse section 8 the sum of the latter material, square shallow cast-iron pans They are, however, very wet after their repeated with shifting covers, open wrought-iron pans with batiis, whilst it is necessary that, for stamping, 05,5-8, 57, 15:4, 13.5, 39-6, and 10.0, equal to est covers, copper tubes, pot clay, and other they should be perfectly dry. Provision has been 90 05, multiplied by of 1.5, the common inparaphernalia for the carrying out of the baking made for this difficulty. In the next apartment, terval, or •5, gives 45.025 for the semi-area of that

section. business previonsly adverted to. The oven then, the drying-rooi, is a drying stove, a cast-iron open

These sums of the results of the ordinates it may be imagined, is already heated by means of bel, about seven feet in length and four in widtha Jocke's patent furnace, and there is nothing at a guess-resting upon brickwork, and having a

multiplied by their respective numbers in each bat to xapply it with the rich batch to be acted tire and Mue beneath it. This is covered with beech

• The figures in the horizontal columns give respectively wa. Well, the four journies are now once more wood sawdust-found to answer the purpose the orili rates for the transverse sections ; and those in the wired, and they are placed this time in a malo. I best—and has upon it sieves and other such like I vertical culumus the ordinates for the horizontal sections.

No. VIII.

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outside of the extreme sections, are the thin iron flotation is parallel to the constructed load water. / which is 4596, and subtract 103.95 from it,

horizontal column are placed to the right in the respectively, and the sum of the results, 1832.0, Putting for A, B, and C their values, as given vertical column headed "areas." We must, carried to the left side of the table, will, when by the equations on page 104, the sun becomes however, bear in mind that these quantities are multiplied by 4.2 and ·5, give the displacement in

+

mait not the semi-areas of the several transverse sec cubic feet for one side of the ship.

az-2a2 + a,

6 tions; in the present example they are numerically The quantity 1832.0 is the same as that ob.

ግሽ ms the same as the complete areas of those sections, tained for the sum of the quantities in the vertical

12 in consequence of one-third of the distance be column headed “ Multiples of Areas.” This shows tween the horizontal sections being 4; for multi-that the displacement found by obtaining the areas m plying by this fraction, the result is one-half the of the horizontal sections, regarding them as ordiarea of the section, and then multiplying by 2 nates to a curve which forms the boundary of an which is the area of the part between P, N, and for both sides gives the same number as is found area representing the displacement, is the same P.N.,, (shaded in the figure). in the column. as that found by obtaining the areas of the vertical

To find the area of the portion contained be. To obtain the displacement from the column sections, regarding these as ordinates to a curve tween the ordinates PzN, and P,N,; we have headed “ areas,” these areas, or areas divided by which forms the boundary of an area also re- only to write a, for a, in the above equation and a constant number, might, as we have before presenting the displacement.

it becomes stated, be represented by the ordinates of a curve, The two results should therefore in all cases be

mr the line of abscisse being the middle line of the identical, or the calculations are incorrect.

12

{ 5a;+8a – a 'half-breadth plan, and the ordinates placed at the respective transverse sections, the areas of which obtain the displacement of a ship to the load tire curvilinear area is equal to

We have now explained all that is necessary to

The sum of these two portions, that is, the en they represent.

water-line. T'he area of the figure thus formed will represent at the constructed load water-line, and their

Ships, however, very rarely swim

{ 1a +160,+1a,} the displacement divided by the constant number,

12 one-third of the distance between the horizontal draught of water is constantly altering by the sections. The quantities in this column must, consumption and replenishing of stores, in addi

{an + 4a,+ a

+a;} tion to that variation which arises from altera.

3 therefore, be multiplied by the numbers for tions, such as in the equipment for a man-of-war, which is the second rule. finding the area by the common rule, standing and in cargo for a merchant ship; it is, therefore, opposite to them respectively in the second ver

Rule.—To find the curvilinear area between two tical column, and the results placed opposite to for all draughts of water. This is done by means necessary to find the approximate displacement

equidistant ordinates, such as of the shaded por. them in the adjacent column headed “Multiples of of a scale of displacement formed in the following distant ordinates. Multiply the outside ordinate

tion of Fig. 15, in terms of three consecutive equi areas.” The sum of all these numbers, in the pre-manner:-The displacements to the several hori. sent case, equal to 1832-0, when multiplied by 1 of zontal sections are found by methods already adjacent to the shaded portion of the figure by : and then by 4:2, one-third the interval between given, and which will be described ; a line is then and the middle ordinate by 8, add the results their vertical sections, giving for a result 3847.2, under side of the keel of the ship; from this point twelfth of the distance between the ordinates, drawn, and a point in it taken to represent the together, and subtract the other extreme ordinate

from the sum; the remainder multiplied by onewill be the semi-displacement of the ship in cubic

are set off according to scale the heights of the feet. This multiplied by 2 for both sides gives of the keel; at these heights lines are drawn perseveral horizontal sections above the under side will give the area required.

We have already shown that the quantities 7694:1, the displacement in cubic feet for both sides from the L. W. line to upper part of the keel. pendicular to that line; these lines are then 3:6, 55-2, 103-95, 141-5, 1714, 209-7,and 236-95,

or the sums of the vertical columns of large Were there any portions of the ship outside the

taken to represent tons, and their lengths are extreme sections, these should be calculated by proportionate to the number of tons displacement figures in the table page 299, are the areas

of the several horizontal sections divided by to the respective horizontal sections; a fair curve the ordinary rules of mensuration, and added to the above result to give the total displacement. is then drawn through their extremities, from acertain number ; in order, therefore, to find which the displacement may be very accurately

the displacement to the 41 W.L. we have keel and the rudder and post, all of which may be line. In order, however, to find the displacement multiplied by one-twelfth of the distance (1:5 ft.)

leaving 355.65 as a remainder; this quantity safely neglected as inappreciable. The cubic

feet divided by 35—the number of cubic feet of sea

to the 4! W.L. it will be necessary to deduce a water in one ton-gives 219.84 as the total dis

rule for finding a portion only of the curvilinear between the horizontal sections, and one-third the area P, P, N, N, when there are three equidis- 186.7162 for the displacement in cubic feet to the

distance between the vertical sections, gives placement in tons to the load water-line. To obtain the displacement by “horizontal sectant ordinates (lig. 15).

44 W.L., and the corresponding number of tons is tions," the ordinates in each horizontal column

5:3347. To obtain the displacement to the 4 W.L., are multiplied by the number opposite to it in the

3:6, 55.2, and 103.95 are regarded as the ordinates second vertical column from the left; and the

to a curve, and multiplied by 1, 2, and respecresults placed immediately to the right of the

P,

tively, and then multiplying by the proper propor. ordinates, written in red ink, and as is shown in

tion of the distances between the horizontal and the table in large figures.

vertical sections, the displacement in cubic feet is Thus :—The ordinates in the horizontal column

found to be 689 535, and in tons 19.701. The 1 are multiplied by ļ, those in column 1ļ by 2;

whole of which calculations will be readily made and so forth for all the horizontal columns.

out from the table. In obtaining the displace. When these are completed, the results will form

ment to the 34 W.L. the ordinates 3:6, 55'2, a series of vertical columns; and it will be seen N,

Na

Ng 103.95, and 141-5, are multiplied by 1, 3, 8, and that the ordinates corresponding to any horizontal

1 respectively, in accordance with the third rule section, will have been multiplied respectively by In our investigations on page 101 we obtained for finding a curvilinear aren; the sum of which the numbers opposite to them in the second ver- by the summation of a large number (2n) of very results or 622:55 when multiplied by the proper tical column from the left; the sam, therefore, of small trapeziums, the area of the entire figure proportions of the distance between the horizontal the results in the vertical columns, when multi- between P, N, and P, Ny; but it is clear that we and vertical sections, will give 1470-7743 for the plied by one-third the interval between the ver could have obtained any portion of it, such as number of cubic feet displacement to that Line tical sections, give respectively the semi-area of that between the ordinates P, N, and P, N.. equal to 42:0221 tons. the corresponding horizontal sections. Thus, the

In this case we should have n trapeziums to

To find the displacement to the 3rd W.L. The sum of these quantities in the vertical column sum, instead of 2n as before taken.

displacement between the L.W.L. and 3 W.L. is headed L. W.L., or the sum of .05, 1.8, 1.9, 5.8, 6.0, &c., 3:8, 4:0, and .05, altogether equal to

Referring to page 104 we find that the sum of found by multiplying 236.95 by 1, 209 7 by 4,

and 171.4 by 1, and adding the results together, 236-95, when multiplied by 4.2 will give the the n trapeziums will be equal to

giving 1217•15; then multiplying in the usual semi area of the load water-section.

{

+ &c. to n terins manner, there results 5238·03, which is the These sums for the several horizontal sections,

number of cubic feet displacement between the inserted at the foot of the respective columns, are

L.W.L, and the 3 W.L., and the number of tons 36, 55-2, 103.95, 141-5, 171.4, 209.7, and 236.95, ** 1+3+5+7+ &c. to n terms }

in the same is 149:658; this number subtracted and to proceed as before, instead of multiplying

from the total displacement, 219-84, leaves 70.182 each of these quantities by 4.2 to obtain the semi

cm3 (
1? + 2? + 3+ &c.... + m2

for the displacement to the 3 W.L. area of the sections, we shall regard them as the

The same result would be obtained by making ordinates of a curve, the line of abscissæ of which

Bm? Cms = A xm +

1) is the middle line of the body plan, and the posi.

the quantities 3:6, 55•2, 103.95, 141:5, and 171.4, 1+ 3^2

the tive equidistant ordinates of a curve, and find. tions of these ordinates, the intersections of this line by the horizontal sections.

ing the curvilinear area in the usual way. for all values of n, and when n is infinitely large,

The displacement between the L.W.L. and the These quantities must, therefore, be multiplied it is equal to

2 W.L. is obtained in the same way as that be. by the numbers standing at the head of the ver

Bm? Cm
Ant

1
since Zero.

tween the upper part of keel and the 4! W.L. tical columns, viz., by 1, 2, 1, 2, 14, 4, and 1

viz., by multiplying 236.95 by 5, 209.7 by 8, add

FIG.15.

P

m m
+ +
n

ns}

+

+

2

+

3

2n?

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