Popular Science Monthly/Volume 38/January 1891/The Development of American Industries Since Columbus: Iron and Steel Industry II
|THE DEVELOPMENT OF AMERICAN INDUSTRIES SINCE COLUMBUS.|
II. IRON MILLS AND PUDDLING-FURNACES.
By WILLIAM F. DURFEE, Engineer.
IN these days of steam-engines, railways, and steam navigation—telegraphs, telephones, and electric lights—it is hard to understand a civilization which in literature and the fine arts has not been surpassed, yet had none of the above-named essentials of modern fast living and rapid work, and which possessed no better methods of manufacturing iron than those already described.
It will be evident to the most superficial observer that these methods were not calculated to produce merchantable bar iron either rapidly or cheaply, and this fact would be the more manifest as the bars or rods decreased in size. Therefore, as the requirements of trade were mainly for bars and rods of moderate dimensions, from which to forge nails, draw wire, and manufacture multitudes of the smaller articles of hardware for which the settlement of new countries had created a growing demand, nothing could have been more natural than that the efforts of mankind to meet the requirements of the time should have resulted in the invention of the "slitting-mill." We have no precise information as to the date of this invention, and none whatever respecting its inventor. It is very probable that the slitting-mill was invented in Sweden, and carried thence into Germany, Belgium, and England, whence it found its way to the colony of Massachusetts Bay, where the first "slitting-mill" used in America was put in operation some time prior to 1731. Swedenborg, in his De Ferro (1734), speaks of "slitting-mills" in Sweden, Germany, Belgium, and England, but does not refer to their origin, and says nothing whatever of grooved rolls. Slitting-mills were introduced into England as early as 1697.
A "slitting-mill" comprises two principal mechanisms, which are well illustrated by Fig. 17, which, together with Figs. 16 and 18, we have taken from Recueil de Planches sur les Sciences et les Arts. Paris, 1765. In Fig. 17 will be seen—
1. A pair of plain cylindrical rolls, C D, placed the one above the other, each receiving motion, independent of the other, from a water-wheel, there being one on each side of the mill, whose shafts are seen at E and O. These rolls could be adjusted so that the distance between their adjacent surfaces might be varied within certain limits. These rolls equalized the thickness of the rough forged bar and prepared it for the next operation.
2. The "slitting-mill" proper, seen between the letters N and V'. This consisted of two horizontal shafts, placed in the same vertical plane with the axes of the rolls D C, and coupled to them by spindles y Y', and coupling boxes u u' and V V'. On these shafts were fixed disks of steel, called "cutters," of a thickness equal to the width of the bar or rod desired; the edges of the
Fig. 17.—Interior of an Early Slitting-Mill. (1704.)
"cutters" on each shaft entered closely between those . on the other, thus acting with reference to each other like the blades of rotary shears, which in fact they were; and, if the end of a flat bar of hot iron was thrust against the approaching edges of the rotary cutters, it would be immediately drawn between them, and in its passage it was "sheared" or "slit" (hence the name "slitting-mill") into a number of bars or rods of the same width as the thickness of the cutters in use at the time. The shafts carrying the cutters could be taken from the frames or "housings" in which they revolved, and the cutters could be removed and replaced by others thicker or thinner as desired. The slitting-mill in Fig. 17 gets its motion from the same water-wheel shafts, E O, that drive the rolls C D.
John Houghton, in his Husbandry and Trade Improved, printed in 1697, speaks of rolling and slitting mills as "late improvements"; speaking of the operation of "slitting" iron bars that have been hammered out in a "blomary," he says: "They are put into a furnace to be heated red-hot to a good height, and then brought singly to the rollers, by which they are drawn even, and to a greater length; after this another workman takes them while hot, and puts them through the cutters, which are of divers sizes, and may be put on or off according to pleasure. Then another lays them straight, also while hot, and when cold binds them also into fagots, and then they are fit for sale."
By comparing this description of John Houghton's with Fig. 17, the original of which was published sixty-eight years later, it will be evident that very little change had taken place in the construction of slitting-mills in that period.
The furnace (whose door is seen at Y, in Fig. 17), in which the rough-hammered bars from the "blomary" were heated preparatory to rolling, was peculiarly constructed, and had fireboxes, P R, on each end. Sections of this furnace are shown in Fig. 18; No. 1 being a longitudinal vertical section through the fire-boxes, P R, and the reverberatory heating-chamber Q; No. 2 a vertical transverse section of the heating-chamber Q, the chimney q q, and its hood q. It will be observed that the chimney of this furnace is not placed, as in a modern iron heating-furnace, at one end of the heating-chamber, while the fire-box is at the other; but that it is located outside and in a measure detached from the body of the furnace, and that the products of the combustion of the wood (which was the only fuel used) burned in the two fire-boxes P R, after traversing the heating-chamber Q, could only reach the chimney by passing out of the door Y. This arrangement was not calculated to produce a very rapid combustion of the fuel, and therefore large fireboxes were necessary. The dimensions of this furnace would not be thought small even at the present time, for the heating-chamber Q was ten and a half feet long and seven feet wide, and the two fire-boxes were each four feet square.
Fig. 18.—Longitudinal and Transverse Sections of Heating Furnace in a Slitting-Mill (1764.)
Fig. 19.—Old Form of Slitting-Mill in Use in Sweden in 1734.
mill of this kind. It will be noted that the top roll and set of cutters were driven from one water-wheel, and the bottom roll and cutters from another; it will also be observed that the iron was evidently heated directly upon the coal. Swedenborg says: "In the vicinity of Liége are a few works in which iron is rolled out and cut into small rods; and in Germany and England there is similar machinery, constructed as shown in Fig. 19, which vividly represents the whole operation.
"The furnace shown is simply constructed, and is divided into two parts, beneath each of which is an ash-pit. The iron is thrown into the furnace upon the mineral coal (carbones fossiles) and the bars are placed across one another obliquely, so that the flame and heat will have access to all sides of them. The roof of the furnace is formed into an arch. When the pieces of iron are heated by the direct action of the coal, and by the heat reverberated from the roof of the furnace, they are removed and run through two steel rolls."
By comparing this mill and furnace with those illustrated in Figs. 17 and 18, it will be evident that in the thirty-one years which intervened between the publication of De Ferro and Recueil de Planches sur les Sciences et les Arts important progress had been made in the construction of both mills and furnaces.
We have been thus particular in explaining the construction of the early European slitting-mills because it is certain that many of the ideas embodied in the first American slitting-mill were derived therefrom.
Industrial history is indebted to William H. Harrison, of Braintree, Mass., for the preservation of a record of the details of construction of certainly one of the earliest, if not actually the first, rolling and slitting mills built in America. The general plan and elevation of the machinery, as also of the furnace employed in this mill, are shown in Fig. 20, and it will be noted that the natural tendency of the American mechanician to improve on what had already been accomplished asserted itself in this case. The designer while retaining many features of previous mills—such as wooden gearing, the use of two under-shot water-wheels, one of which drove the top set of cutters and the bottom roll while the other drove the bottom set of cutters and the top roll—yet made some important improvements in the rolls by increasing their length and making offsets in them by which iron of vary ing thickness could be made without changing their adjustment; and he also "chilled" one end of the rolls. The furnace was a marked improvement over any before described, and was quite similar in idea to many in use at the present day; it had a "fire-box" (in which "pine sticks" were used as fuel), a "heating-chamber," and a "chimney." This mill was erected "at Middleboro, Mass., for Peter Oliver, one of the crown Judges in the province, and a brother of Andrew Oliver, the Lieutenant-Governor, in the year 1751."
Fig. 20.—Plan of a Rolling-Mill Built at Middleboro, Mass., in 1751.
Mr. Harrison says, in concluding his very interesting paper: "The drawing was made under the supervision of S. Wilder, Esq., of New Castle, Pa., a retired iron manufacturer, who worked in this mill in 1818, and gave the writer the principal dimensions and the method of operating. As to whether this mill—in the year 1818—was precisely the one built in 1751, Mr. Wilder states that it is likely there had been some renewals of the wood-work, but most of the iron-work was the original. It was impossible to break down the mill, from the fact that, if a heavy piece or a pair of tongs were passed in, the effect would be—after some squeaking of the timber-wheels—to stop everything."
The claim made that this rolling-mill was the first in America can not be substantiated, for, according to the evidence adduced, it was not erected until 1751; but it is certain that there were already several slitting-mills in operation in the colonies, as is proved by the certificates transmitted to the Commissioners for Trade and Plantations by the Governors, Lieutenant-Governors, or commanders-in-chief of his Majesty's colonies in America, in pursuance of an act of the twenty-third of his present Majesty's [George II, 1750] reign, containing accounts of any mill or engine for slitting or rolling of iron, and any plating-forge to work with a tilt-hammer, and any furnace for making steel, erected in any of his Majesty's colonies in America":
|Mill or engine for
slitting or rolling iron.
|Plating forge to work with
|Furnace for making|
|Maryland||. . . . . . . . . . . . . . .||1, with two tilt-hammers.||. . . . . . . . . . . . . . .|
|New Jersey||1, not now in use.||1, not now in use.||1, not now in use.|
|New York||. . . . . . . . . . . . . . .||1""||. . . . . . . . . . . . . . .|
|Connecticut||. . . . . . . . . . . . . . .||1, 1, 1, 1, 1, 1||1|
|Massachusetts Bay.||1, 1||1||1|
By these certificates of 1750 it appears that in all the colonies there were four slitting-mills, two of which were in Massachusetts; and as Judge Peter Oliver's mill was not erected ("by special privilege") until 1751, it could not have been one of them, and for the same reason it is certain that it was not the first rolling-mill in America. Nevertheless the paper of Mr. Harrison is instructive and valuable, inasmuch as it gives us the only reliable technical information we have relative to the construction and operation of rolling and slitting mills in colonial times. In addition to the leading constructive features of this mill, we are given some facts regarding its administration, and are told that "about eight men were employed, at about one dollar per day; six heats, of about eight hundred pounds each, were made in twelve hours' running. One pint of rum was consumed for each heat, or more, according to the weather. The value of the forge iron was one hundred dollars per ton; nail-rods, one hundred and twenty dollars; and nails, twelve and a half cents or ninepence per pound. The nail-rods were put up in bundles of fifty-six pounds, and the nailers, who had their little shops around in the country, were expected to bring back fifty pounds of headed and pointed nails, receiving "store-pay" of calico, tea, rum, etc.
From this account it appears that "rum," in quantity proportioned "to the weather," was regarded as a necessary stimulant, to be furnished the workmen to enable them to properly perform their work. This custom, which was in fact universal in New England at the time, seems to have had the sanction of several generations, for the New Haven colonial records tell us that "a proposition made in May, 1662, 'in ye behalfe of Capt. Clarke, that wine and liquors drawn at the iron workes might be custome free,' was allowed to the extent of one butt of wine and one barrel of liquors, and no more."
The act of 1750 was pretty generally enforced in the colonies, and the further erection of rolling and slitting mills prevented. James Hamilton, Lieutenant-Governor and Commander-in-Chief of the Province of Pennsylvania, and William Franklin (son of Benjamin Franklin), who was the royal Governor of the Province of New Jersey (1762 to 1776), were especially zealous in enforcing this act. Hon. Edward D. Halsey, in his History of Morris County, tells us that "a slitting-mill was erected at Old Boonton, on the Rockaway River, about a mile below the present town of Boonton, in defiance of the law, by Samuel Ogden, of Newark. The entrance was from the hill-side, and in the upper room first entered there were stones for grinding grain, the slitting-mill being below and out of sight. It is said that Governor William Franklin visited the place suddenly, having heard a rumor of its existence, but was so hospitably entertained by Mr. Ogden, and the iron-works were so effectually concealed, that the Governor came away saying that he was glad to find that it was a groundless report, as he had always supposed."
From the passage of the act of 1750 to the Revolution the iron industry of America was chiefly confined to the manufacture of pig and bar iron in the furnaces, forges, and mills already erected, and of castings from the blast-furnaces.
Israel Acrelius (who visited America in 1750-1756), in his History of New Sweden, when describing the iron-works of Pennsylvania, says: "The workmen are partly English and partly Irish, with some few Germans, though the work is carried on after the English method. The pig iron is smelted into 'geese' (gäsar), and is cast from five to six feet long and a half foot broad, for convenience of forging, which is in the Walloon style. The pigs are first operated upon by the finers (smelters). Then the chiffery, or hammer-men, take it back again into their hands and beat out the long bars. The liners are paid 30s. a ton, the hammer-men 23s. 9d. per ton—that is to say, both together, £2 13s. 9d. The laborers are generally composed partly of negroes (slaves), partly of servants from Germany or Ireland bought for a term of years. . . . For four months in summer, when the heat is the most oppressive, all labor is suspended at the furnaces and forges."
About 1732 Colonel Spotswood erected some air-furnaces at a place called Massaponux, in Virginia, and used them "to melt his sow iron, in order to cast it into sundry utensils, such as backs for chimneys, andirons, fenders, plates for hearths, pots, mortars, rollers for gardeners, skillets, boxes for cart-wheels, and many other things. And, being cast from the sow iron, are much better than those which come from England, which are cast immediately from the ore for the most part. . . . Here are two of these air-furnaces in one room, that so in case one want repair the other may work, they being exactly of the same structure." It is said that in 1760 about six hundred tons of iron were smelted in Spotswood's furnaces, most of which was sent to England.
About 1750 Baron Henry William Stiegel came to Pennsylvania from Germany, "with good recommendations and a great deal of money." Soon after he purchased a tract of land in Lancaster County and laid out the town of Manheim; here he built a furnace, and named it after his wife, Elizabeth; some time afterward he built another furnace at Schaeff erstown, Lebanon County, and it was here that he cast stoves (made of six plates of iron), which were among the first made in the country. The baron fully appreciated the value of advertising, and on each of the stoves he cast the following couplet:
"Baron Stiegel ist der Mann,
Der die Ofen machen kann"—
which signifies, "Baron Stiegel is the man who knows how to make stoves"; but, notwithstanding his skill and enterprise, he failed in his business. This result was due in a great degree to the difficulty of making prompt collections, and to the general stagnation of business due to the political complications with the mother-country. Elizabeth Furnace finally came into the possession of Robert Coleman, who cast shot, shells, and cannon for the Continental army. Some of the credits in his account with the Government are decidedly interesting. On November 16, 1782, appears the following entry: "By cash, being the value of 42 German prisoners of war, at £30 each, £1,200," and on June 14, 1783: "By cash, being the value of 28 German prisoners of war, at £30 each, £840."
During the Revolutionary War the manufacture of iron made little technological progress. Such establishments as possessed the requisite skill cast cannon and mortars, and the iron ammunition for the same, for that army which controlled them for the time being. One of the most notable events connected with the manufacture of iron during these years was the making of the great iron chain which in 1778 was stretched across the Hudson River at West Point to prevent the passage of British vessels. Lossing, in his Field Book of the Revolution, gives a very interesting account of this work, of which we can quote only the leading facts. "The iron of which this chain was constructed was wrought from ore of equal parts from the Sterling and Long mines in Orange County. The chain was manufactured by Peter Tuwnsend, of Chester, at the Sterling Iron Works in the same county, which were situated about twenty-five miles back of West Point. The chain was completed about the middle of April, 1778, and on the 1st of May it was stretched across the river and secured. It was fixed to huge blocks on each shore, and under cover of batteries on both sides of the river." "It is buoyed up," says Dr. Thacher, writing in 1780, "by very large logs of about sixteen feet long, pointed at the ends, to lessen their opposition to the force of the current at flood and ebb tide. The logs are placed at short distances from each other, the chain carried over them, and made fast to each by staples. There are also a number of anchors dropped at proper distances, with cables made fast to the chain to give it greater stability." The total weight of this chain was one hundred and eighty tons. Mr. Lossing visited West Point in 1848, and saw a portion of this famous chain, and he tells us that "there are twelve links, two clevises, and a portion of a link remaining. The links are made of iron bars, two and a half inches square, and average in length a little over two feet, and weigh about one hundred pounds each."
The manufacture of nails was one of the household industries of New England during a large part of the eighteenth century. James M. Swank, in Iron in All Ages, quotes from Nehemiah Bennet's description of the Town of Middleborough, Plymouth County, Massachusetts (1793): "Nailing, or the business of making nails, is carried on largely in the winters, by farmers and young men, who have little other business at that season of the year." Speaking of the early attempts to manufacture tacks, the same authority gives the following from the Furniture and Trade Journal: "In the queer-shaped, homely farm-houses, or the little contracted shops of certain New England villages, the industrious and frugal descendants of the Pilgrims toiled providently through the long winter months at beating into shape the little nails which play so useful a part in modern industry. A small anvil served to beat the wire or strip of iron into shape and point it; a vise worked by the foot clutched it between jaws furnished with a gauge to regulate the length, leaving a certain portion projecting, which, when beaten flat by a hammer, formed the head. By this process a man might make, toilsomely, perhaps two thousand tacks per day." Arnold, in his History of the State of Rhode Island, claims that "the first coldcut nail in the world was made in 1777 by Jeremiah Wilkinson, of Cumberland, R. I., who died in 1832, at the advanced age of ninety years." Bishop, speaking of Wilkinson's tacks, says: "They were first cut by a pair of shears (still preserved) from an old chest-lock, and afterwards headed in a smith's vise. Sheet iron was afterwards used, and the process extended to small nails, which he appears to have been one of the first to attempt. They were cut from old Spanish hoops, and headed in a clamp or vise by hand. Pins and needles were made by the same person during the Revolution from wire drawn by himself." Such was the genesis of the manufacture of nails in America; an industry now of the first importance, and which in 1889, after the lapse of little more than a century, produced over eight hundred million pounds of iron, steel, and wire nails, representing a consumption of this absolutely indispensable manufacture, for the past year, at the rate of over twelve pounds for each individual inhabitant of the United States. As nails enter as a component factor into all structures for domestic, manufacturing, and trade uses, this enormous consumption may be taken as a fair index of the development of the country during the past hundred years.
The adoption of the Constitution in 1787, followed by the enactment of the first national patent law in 1790 (previous to the establishment of a national government the several colonies had issued patents for meritorious inventions), powerfully stimulated the inventive genius of the people, and it soon became evident that America was destined to surpass all other nations in the invention and manufacture of labor-saving machinery.
One of the most important improvements in the manufacture of articles of metal, of which a large number were required of the same kind, was developed by Eli Whitney, the inventor of the cotton-gin, who, disappointed in his expectations relative to that machine, turned to the manufacture of small-arms for the United States Government. In 1798 he erected at Whitneyville, near New Haven, Conn., the first manufactory of fire-arms in which each part was made so exactly to the prescribed dimensions that it would fit its intended place in any one of thousands of muskets. Mr. Whitney not only conceived the ideas of the possibility and economic advantages of such perfect workmanship, but invented the system and much of the machinery by which it was practically accomplished. "Whitney's interchangeable system" has been applied successfully to the manufacture of clocks and watches, sewing-machines and steam-engines, and is universally recognized as indispensable whenever accuracy and economy are to be combined with a large production.
Swank gives the following description of the Sterling Iron Works (already mentioned as the place where the West Point chain was forged), translated from a book published in Paris in 1801, written by the Marquis de Crevecœur, who was in the French service in the French and Indian War and afterward traveled extensively in this country:
"Hardly had we put our horses in the stable than Mr. Townsend, the proprietor, came to meet us with the politeness of a man of the world. Having learned that the object of our journey was to examine attentively his different works, he offered to show us all the details, and at once led us to his large furnace where the ore was melted and converted into pigs of sixty to one hundred pounds weight. The blast was supplied by two immense wooden blowers, neither iron nor leather being used in their construction. This furnace, he said, produced from two thousand to twenty-four hundred tons annually, three fourths of which are converted into bars, the rest melted into cannon and cannon-balls, etc. From there we went to see the forge. Six large hammers were occupied in forging bar iron and anchors and various pieces used on vessels. Lower down the stream (which afforded power to the works) was the foundry with its reverberatory furnace (air-furnace). Here he called our attention to several ingenious machines destined for different uses. The models he had sent him, and the machines he had cast from iron of a recently discovered ore, which, after two fusions, acquired great fineness; with it he could make the lightest and most delicate work. 'What a pity' he said, 'that you did not come ten days sooner! I would have shown you, first, three new styles of plows, of which I have cast the largest pieces, and which, however, are no heavier than the old-fashioned. Each of them is provided with a kind of steelyard, so graduated that one can tell the power of the team and the resistance of the soil; second, I would have shown you a portable mill for separating the grain from the chaff; followed by another machine by which all the ears in the field can be easily gathered without being obliged to cut the stalk at the foot, according to the old method.' From the foundry we went to see the furnaces where the iron is converted into steel. 'It is not as good as the Swedes',' said Mr. Townsend, 'but we approach it—a few years more of experience and we will arrive at perfection. The iron which comes from under my hammers has had for a long time a high reputation, and sells for £28 to £30 per ton.' After having passed two days in examining these diverse works and admiring the skill with which they were supplied with water, as well as the arrangements for furnishing the charcoal for the different furnaces, we parted from Mr. Townsend."
On June 27, 1810, Mr. Clemens Rentgen, of Pikeland, Chester County, Pennsylvania, obtained a patent for "rolling iron round, for ships' bolts, and other uses," by the following method: "This machine consists of two large iron rollers, fixed in a strong frame. Each roller has concavities turned in them, meeting each other to form perfectly round bolts, of from half an inch to one and three quarter inches, or any other size, in diameter, through which rollers the iron is drawn from the mouth of the furnace with great dispatch, and the iron is then manufactured better and more even than it is possible to forge it out. The force applied to the end of these rollers is like that applied to mills."
Swank states that W. H. Wahl, Ph. D., Secretary of the Franklin Institute (who is a descendant of Mr. Rentgen), showed him the original patent, and informed him that Mr. Rentgen "rolled round iron as early as 1812 or 1813, some of which was for the Navy Department of the United States Government"; and he adds, "The fact that a patent was granted to him as late as June 27, 1810, for a machine to roll iron in round shapes, would seem to furnish conclusive proof that Cort's rolls had not then been introduced into the United States." About the beginning of the present century the steam-engine (two or three steam-engines had been imported and used for draining mines prior to the Revolutionary War) as a motive power for driving mills and factories began to attract attention. The period of its introduction is worthy of mention, as it has played a very important part in the development of the iron and steel industries of this country.
According to Swank, "the first rolling-mill erected in the United States to 'puddle' iron, and roll it into bars, was built by Col. Isaac Meason, in 1816 and 1817, at Plumsock, on Redstone Creek, in Fayette County, Pennsylvania. Thomas C. Lewis was the chief engineer in the erection of the mill, and George Lewis, his brother, was the turner and roller. They were Welshmen. ... The mill contained two 'puddling furnaces,' one 'heating furnace,' one 'refinery,' and one 'tilt-hammer.' Raw coal was used in the 'puddling' and 'heating furnaces,' and coke in the 'refinery.'"
In the early practice in this country the operation of "puddling," by which cast iron is converted into wrought iron, was usually preceded by a process called "refining," which was effected by means of an apparatus called a "refinery" a vertical section of one of the latest and best forms of which is shown in Fig. 21. It consisted of a basin or hearth, b, in which a fire of charcoal or coke was built, the fuel being carried above the level of the water-cooled tuyères, g g. On this mass of ignited fuel a charge of a ton or a ton and a half of pig iron was thrown, over which fuel was heaped, and the blast (which was regulated by the valves, k k) was then turned on. In about one hour and a half the pig iron was melted, and its upper surface as it lay in the hearth was exposed to the action of the blast (oftentimes in the larger refineries there were six tuyères, three on a side, but in some of the oldest refineries there was but one tuyère); this effected the oxidation and removal of considerable of the carbon, most of the silicon, and a portion of the sulphur, a large amount of "slag" being formed. About two hours after the commencement of the operation the metal was "tapped out" on to the "running-out bed," which was a shallow trough made of very thick castings; a section of which is shown at n. These castings were provided with flanges, which rested upon the sides, o o, of a box or channel, p, filled with water to cool the running-out bed, and promote the rapid solidification of the liquid refined iron; and as soon as this was accomplished the final cooling was hastened by a jet of water forcibly thrown upon the upper surface of the metal from a hose. This caused the "cinder" on this surface to separate in a great degree from the refined metal, which, when perfectly cool, was broken up into pieces of manageable size. The fracture of "refined metal" was white, inclined to a silvery luster, and oftentimes more or less porous or "honey-combed" near the upper surface, The purpose of this "refining" was, as the name suggests, the purification of the metal previous to its being treated in a puddling-furnace for final conversion into wrought iron. At the present day the "refinery" is rarely employed, improved methods having rendered it unnecessary.
The invention of the "puddling process" is usually ascribed to Henry Cort, of Gosport, England, who patented it in 1784. This process was a great improvement over that of the "blomary fire," inasmuch as the labor was diminished, and, as the metal was not in contact with the fuel, therefore raw mineral coal, which was much cheaper than charcoal, could be used with natural draught, thus dispensing with all blowing machinery. The process, as practiced on its introduction into America, consisted substantially of melting refined pig iron on the sand bottom of a reverberatory furnace, and stirring the pool (or "puddle," whence the name of the process) of molten metal until it became converted into a granular, pasty mass of wrought or forgeable iron, as the result of the decarbonizing action of the heated air passing through the furnace and over the metal. This granular mass of metal was divided by the "puddler" (as the workman was called) into several separate "balls," or "loups," which were taken in turn to a "shingling hammer," and "shingled" into "blooms"; this last operation being precisely similar to the shingling of the "ball" from a blomary fire, already described. Figs. 22 and 23 are respectively vertical and horizontal longitudinal sections of one of the earlier forms of "puddling-furnace," in which e is the sand bed of the puddling-chamber, d the "bridge-wall" which separated the fuel on the grates b of the "fire-box" from the iron in the puddling-chamber e, i is the chimney-flue, and k a lever for raising the door j. In some of the early puddling-furnaces in New England and eastern Pennsylvania the fuel used was dry split wood; and as late as 1858 dry pine wood was used for puddling and heating at the Hurricane Rolling-Mill and Nail-Works in South Carolina. This was probably the last instance of the use of wood as a fuel for such purposes in the United States.
Soon after the introduction of the puddling process into this country, Mr. Samuel Baldwyn Rogers, of Nant-y-glo, Monmouthshire, England, made very important improvements in the construction of puddling-furnaces, by substituting iron plates for the original sand bottoms of their puddling-chambers; and in the conduct of the process, by using iron-ore as the chief source of the oxygen necessary to decarburize the melted pig iron. This ore was packed around the sides of the interior of the furnace, and the bottom plates were protected by a layer of oxide of iron. These improvements more than doubled the daily production from a furnace, and at the same time a superior quality of iron was made.
Mr. Rogers encountered a great deal of ridicule in attempting to introduce these improvements, which were pronounced impracticable and of no value by many of the leading iron-masters of England; and, as he failed to protect his rights by patents, the only reward that he ever received for inventions that have been of vast benefit to mankind was the nickname "Old Iron Bottoms" which was bestowed upon him by those of his contemporaries who fully believed that they had become possessed of all desirable knowledge, and were, in fact, too wise to learn. Unfortunately for our country, a few of the descendants of these wise fools, who were patriotic enough to "leave their country for their country's good," found their way to America, and are honoring their ancestry by sneering at all ideas and methods that are not hoary with antiquity and moldy respectability. In spite of such counsels in the past, the improvements of Mr. Rogers found their way into use in America and the world at large, and for the last fifty years there has not been a puddling-furnace as originally constructed by Cort in existence.
A very good idea of the appearance and construction of the puddling-furnace in common use in the "puddle-mills" of England and America is conveyed by Figs. 24 and 25. Fig. 24 is a side elevation of the furnace, whose interior form is shown by dotted lines. The whole of the brick-work is inclosed in a casing of cast-iron plates, securely bolted together. The door of the working-chamber is seen in the center (and at C, Fig. 25), counterbalanced and operated by a lever and chain, and below it the "tap-hole," by which the "cinder" made in the process is "tapped off"; to the left is seen the "stoke-hole," and just to the right of it is shown, in dotted lines, the outline of the "bridge-wall" separating the "fire-box" on the left from the "working-chamber" in the center of the furnace. The chimney (shown at the right of the cut, broken in three places for convenience of illustration) is usually from thirty to forty feet in height, provided with a damper operated by a lever at its top, and its flue is usually eighteen inches square. Fig. 25 is a section of the furnace (on line G, H, Fig. 24), showing the form of its interior in plan, and the relative position of "fire-grate," "working-chamber," and "chimney-stack." In mills driven by steam power it is not now uncommon to place a horizontal cylindrical flue-boiler over each puddling and heating furnace, and generate the steam required to run the mill by passing the heat, that would otherwise go to waste up the chimney, underneath the boiler, and thence through the flues to the chimney-stack. This construction was the invention of the late John Griffen, who at the time of his death (January 14, 1884) was General Superintendent of the Phoenix Iron Company at Phœnixville, Pa. The idea of utilizing the waste heat of puddling and heating
Fig. 24.—A Modern Puddling-Furnace.
furnaces for the making of steam was, however, quite old at the time he brought out his arrangement.
When, in 1846, Mr. Griffen erected at Norristown, Pa., for Messrs. Moore & Hooven, the first mill in which all the steam was generated in boilers placed over the furnaces, the wise fools were in strong force; and Swank tells us that "Mr. Griffen met with much opposition from observers while employed in constructing the mill upon this plan, and many predictions were made that the new arrangement would prove a failure. It was a great innovation on the practice then prevailing, but it was a complete success." Whereat the wise fools who had been posing as "observers," promptly swallowed all their observations, and with the characteristic agility of their race turned each a back somerset,
Fig. 25.—Plan of a Modern Puddling-Furnace.
and, coming up blandly smiling, with the remark "We always told you so," forthwith proceeded to foolishly praise that which they had more foolishly condemned.
The rapid increase of the manufacture of iron in consequence of the introduction of the puddling process naturally called for a
Fig. 26.—The Alligator Squeezer.
more expeditious method than the blows of a "trip-hammer" for expelling the cinder from the "puddle-balls" and forming them into "blooms"; and this necessity resulted in the invention of the "alligator squeezer," which consisted (as shown in Fig. 26) of a lever whose long arm was operated by a crank, the short arm being provided on its under side with a number of angular corrugations, so that it is somewhat suggestive of the jaw and teeth of an alligator. The "ball" from the puddling-furnace was placed between the upper and lower jaws of this squeezer, and the workmen turned it with tongs at each upward movement of the upper jaw (always moving it toward the fulcrum of the lever), thus causing the ball to be forcibly squeezed by each downward movement; and when the operation was completed the most of the liquid cinder had been expelled from the ball, which had assumed the form of a bloom.
Although this apparatus was of sufficient capacity for shingling a very much larger product than the trip-hammer which it displaced, yet it required the assistance of a workman, or "shingler," as he was called; and, as the number of puddling-furnaces increased in the mills, it soon became evident that more rapid and purely automatic machinery for shingling puddle-balls was desirable. This want was supplied by the inventive genius of Henry Burden, of Troy, N. Y., who in 1840 invented the "rotary squeezer." Fig. 27 is an elevation of the original form of this machine, and Fig. 28 is a horizontal section of Fig. 27 on line A B. The construction consisted substantially of a heavy cast-iron casing or "scroll," a a (Fig. 28), firmly attached to four surrounding columns, which stood upon a heavy bed-plate and also sustained a massive casting which formed the upper support and bearing of a vertical shaft to which the heavy cast-iron drum b (Fig. 28) was firmly attached; below the bed-plate is seen (in Fig. 27) the gearing for giving motion to the shaft and drum.
The "puddle-ball" was thrown into the machine at the place indicated by the arrow (Fig. 28), and, as the drum b revolved rapidly to the left, the ball was drawn in between it and the scroll, the teeth on each preventing its slipping; and, as it was carried around by the movement of the drum, the constantly narrowing space caused the ball to be subjected to great pressure, which expelled the liquid cinder and at the same time forced the ball to assume before it was ejected from the machine the form of a cylindrical bloom. In order that the squeezer should accommodate balls of considerable variation in weight, and at the same time exert a powerful end-pressure or "upsetting" during the operation of shingling, a very heavy ring of cast iron (shown in the plane A B, Fig. 27) was made to rest upon the upper end of the mass of metal as it passed through the machine; this ring was kept in position horizontally and guided in its movement vertically by the upper part of the spindle of the drum b. The finished "bloom" was discharged from the "squeezer" at the right-hand side of the opening in the "scroll" through which the "ball" originally entered, and such was the rapidity of the operation that the "bloom" retained sufficient heat at its close to permit of its being passed directly through the "rolls" and rolled into "billets" or "muck-bars" without reheating.
The modern form of the above-described machine differs somewhat from that shown in the illustrations in the arrangement of its driving-gear, but the general principles embodied in the original construction are still retained. Large numbers of Burden Rotary Squeezers "are in use in the rolling-mills of the world, and it may fairly take rank as one of the most important improvements in the manufacture, of iron that have had their origin in America.
Coincident with the improvements in apparatus and methods for producing wrought iron, the general advancement of all the arts, and especially those relating to the manufacture of machinery, created a demand for forgings of a size impossible of execution by the ancient trip and helve hammers; and as a means of supplying this need for uncommonly heavy forgings, the manufacture of the "Nasmyth direct-acting steam hammer" was commenced in the year 1843, by Messrs. Merrick & Towne, at the Southwark Foundry, Philadelphia, Pa. The "Nasmyth hammer" as at first constructed at this establishment, is represented by Fig. 29, in which AAA are the two upright frames of cast iron, which supported a lintel, C, that sustained the steam-cylinder,
Fig. 29.—The Nasmyth Steam Hammer.
D, and its steam-chest, J. The piston-rod, E, was secured at its lower end to the "hammer-block," F F F, which was free to move vertically between, and was guided by, the upright frames, AAA. The valve-gear is shown on the left-hand frame, A, which actuated the valve in the steam-chest, J. The intensity or working force of the blow delivered to the work upon the anvil
Fig.30—A Modern Forge.
varied with the height through which the "hammer-block" was allowed to fall, and this height could be regulated within the limits of the full stroke of the hammer by means of the valve-gear. As soon as the blow had been delivered, the mechanism for effecting the upward movement of the hammer-block came into action. This consisted of a heavy lever, X, which had its fulcrum on the hammer-block, F F. The shorter arm of this lever rested in contact with a vertical bar connected with the valve-gear, P, in such a way that at whatever point of its length the bar chanced to receive a side pressure from the short arm of the lever, X, it caused the admission of steam to the lower end of the cylinder, D, thus causing the "hammer-block" to make its upward stroke. This occurred automatically the instant after the delivery of the blow; the inertia of the weighted end of the lever not being overcome, it moved downward after the "hammer-block" came to rest, and forced its short arm against the vertical bar in the manner described. Such, in brief, were the construction and operation of the first steam hammer built in America, and placed by its builders in the smith's shop of their Southwark Foundry, at Philadelphia, where (Mr. J. Vaughn Merrick writes me) it was "continuously employed till after the sale of the works in 1871."
The original invention of Nasmyth has undergone many changes, and since the expiration of his patents a multitude of modifications having for their object the improvement of its action or its adaptation to some particular variety of work have been brought forward; but they all involve the fundamental ideas of lifting a vertically guided heavy mass, or hammer-block, by the direct action of steam upon a piston with which it is connected, and letting it fall at pleasure upon the work in hand by cutting off the supply of steam and releasing that already beneath the piston; and this combination of ideas and methods originated with James Nasmyth, who, by his invention, augmented the strength of the arm of Vulcan and conferred new powers and possibilities upon the skill of man.
The appearance of a modern forge and all its Vulcanian activities is well represented by Fig. 30, which to an experienced eye presents what may be called a scene of well-regulated confusion, in which, amid smoke and flame, coal and iron, the hissing of steam, beating of sledges, ringing of anvils, and the scorching glare of white-hot metal, the stalwart, half-naked sons of Vulcan strain and sweat at their appointed tasks, while the solid earth for miles around quakes under the ponderous blows of the Cyclopean hammer that
... upheaves its mighty arm
While on the anvil turns the glowing mass—
[To be continued.]
- The earliest publication known to me, in which the use of "rolls" for drawing and shaping metals is described, was written by Giovanni Branca. In his work, Le Machine (published at Rome in 1629), he gives a very curious illustration of a rolling-mill, which, notwithstanding its manifest absurdity, suffices to show that he understood the action of the "rolls" and their advantages. The next mention of the use of rolls for giving shape to metals passed between them is contained in a work by Vittorio Zonca, published at Padua in 1656. In this work Zonca gives an engraving and description of a mill for rolling the double grooved fillets of lead which were used for securing the glass in stained windows. We regret that our limited space prevents us from reproducing these illustrations, neither of which has ever been referred to in any history of the manufacture of metals.
- The First Rolling-Mill in America. A Paper read by William H. Harrison, M. E., at the Hartford Meeting of the American Society of Mechanical Engineers, May 4, 1881.
- A very close approximation to the "grooved roll."
- This is believed to be, if not the first "chilled roll" made, yet the first mentioned in rolling-mill construction.
- A Comprehensive History of the Iron Trade throughout the World, from the Earliest Records to the Present Period. By Harry Scrivenor. London, 1841.
- Cort's patent was taken out in 1783, but the evidence is sufficient and conclusive as to a somewhat extended knowledge and use of grooved rolls on the continent of Europe many years prior to that date.
- This is no exaggeration, as it has been authoritatively stated that the blows of the steam hammers in Woolwich Arsenal have been felt at Greenwich Observatory, about two miles distant.
- I am reminded of a stalwart iron-master who formerly owned a forge in New England, and whose ideas of futurity, apparently, were not perfectly definite—at any rate, he was disposed to be somewhat inquisitive in his way in regard thereto. Whenever he could tempt a clergyman to visit his forge, he would place him immediately in front of the largest furnace, and, as the attendant on a signal raised the door, revealing a temperature within that Nebuchadnezzar's furnace could not have surpassed, he would howl in the ear of the scorched and thoroughly frightened preacher the inquiry, "Is hell any hotter than that?" It has not been recorded that he ever obtained any positive information in answer to this question, the circumstances of which doubtless afforded food for thought to the parties to whom it was put.