sure which they exert, to extend the flanges at the same time that the web is being drawn out by the main rolls. An offset is turned in the side of the large portion of the rolls to receive and form properly the flange as it is extended by the pressure of the friction rolls. The latter are worked each by a screw in a horizontal frame bolted to the side of the housing, the screw being provided with a ratchet lever, to be worked by hand. This enables the thickness of the flanges to be adjusted with precision. With this mill they have rolled girders of 40 inches height, 33 feet long, and feel confident that they could make them 90 feet in length. The essential features of this mill were all to be found in the first train for rolling beams, erected in 1853 at the Trenton Works, New Jersey, but in that case the axes of the driven rolls and of the friction rolls were at right angles to the mill of Petin, Gaudet & Co., which is probably a better working arrangement than the old train at Trenton. The Universal mill is not yet introduced into England, but forms the subject of an English patent now expired, and is undoubtedly destined to fill a very important place in the rolling of iron, and the American ironmaster cannot too soon avail of its advantages before impediments shall be put in its way by the issue of American patents.

Next to rolled girders, or perhaps even more remarkable than these, were the specimens of plate iron contributed from England, France, Germany, and Belgium. John Brown & Co., of Sheffield, exhibited a plate which, after being dressed up to square edges and ends, was 30 feet in length, 2 feet 6 inches in width, and 6 inches thick, weighing 11 tons 5 hundred-weight; and also a piece of a plate which in its original condition was 13 feet long, 6 feet wide, 134 inches thick, and weighed 20 tons. For the production of these enormous masses of iron the machinery is of the ordinary kind in construction, but of dimensions proportionate to the mass of iron to be handled. The size of the rolls is 3 feet, and the handling of the iron is accomplished with facility by the aid of steam cranes and of iron chains winding upon the rolls themselves, which are reversible by a clutch gearing, and make about 20 revolutions per minute.

Other plates of six inches in thickness and of various weights up to five tons were exhibited by the works of Chatillon and of Messrs. Petin, Gaudet & Co., (France,) and of Hoerde, (Prussia.)

Generally there may be said to exist a prevailing willingness and practice in the European works to handle iron in larger masses for every purpose than we do in the United States. For example, Belgium exhibited band iron three-fourths inches wide by 230 feet in length; Prussia exhibited sheet iron of 214 gauge, 48 by 108 inches, and wire rods are frequently to be found in all the departments ranging from 30 to 50 pounds in weight, rolled in trains of the ordinary dimensions, and running at speeds no greater than we employ in the United States, for 15 pound billets. This is accomplished by keeping the billet in many more grooves at the same time than we are in the habit of doing, by an ingenious system of doubling the rods backwards and forwards. This same

method is employed at Montataire, in France, and at other works for rolling braziers' rods, and even bar iron; and this not from the necessities of the order, but from choice, as a matter of economy. In this way one-inch bars of 100 feet in length are regularly produced, and this system, unknown in the United States, can doubtless be introduced with great advantage.

But the most remarkable specimen of rolling was in the English department, exhibited by Richard Johnson & Nephew, of Manchester, in the shape of a coil of No. 3 wire rods, weighing 281 pounds, in length 530 yards, rolled from a single billet. Also a coil of No. 8 wire weighing 200 pounds, 900 yards in length, and a coil of No. 11 wire weighing 95 pounds, in length 790 yards. These wonderful specimens of wire were not, however, produced in an ordinary mill, but were rolled in a machine invented by George Bedson, the manager of the Bradford iron works, in Manchester. This machine consists of rolls in thirteen pairs, placed one behind the other, instead of side by side, as usual, with guides connecting the successive pairs of rolls, and revolving at such relative rates of speed, that the billet being rolled receives the compressing action of the rolls all at the same time. The billet is fed from a long heating furnace at one end of the train of rolls, being charged at the end of the furnace furthest from the train. A Siemens' generator is used to supply the furnace with gas, so as to insure a uniform heat. The average product of the train is 11 tons per day, and the weight of the billets usually rolled is from 80 to 100 pounds. A comparison of the work for six months, with two old-fashioned trains also running in the same works, shows that the waste is reduced from 10 per cent. to 6 per cent., and that the consumption of coal is reduced from 14 hundred-weight, three quarters, 25 pounds, to 8 hundred weight, and 18 pounds per ton, most of which saving is doubtless due to the use of Siemens' furnace, and not to the train; the advantages of the latter consisting in an increase of product of nearly one-half in the increased weight of the billets rolled, and in the economy of the labor employed. A personal visit was made to the Bradford iron works, to see the operation of this ingenious and successful machine. It appears to be all that could be desired, and the action of the rolls upon the iron unquestionably produces a sounder and better rod than when worked by the old process, and this is due doubtless to the higher and more uniform heat at which the rod is finished.1

In the use of wire for telegraphic purposes, for wire suspension bridges, and for cables and ropes, the superior value of long lengths is undeniable. Bedson's machine has therefore the double merit of producing a better article, at a lower cost, than has hitherto been obtained; and it is a matter of regret to those who have become familiar with its novelty and its merits, that it received only the recognition of a silver medal, when it so justly deserved the highest prize.

The same principle has been since successfully applied to the rolling of bar iron.

Borsig, of Berlin, exhibited remarkable specimens of gigantic puddle balls, a single one weighing 1,064 kilograms, (more than a ton,) and he also exhibited a wrought-iron piston without a weld, weighing 590 kilograms, (nearly 12 hundred-weight.) These are not mere tours de force, as he is prepared to take orders at a price which renders it economical to employ his product.

In connection with the large masses of iron with which, as demonstrated in the Exposition, modern industry so much occupies itself, it is proper to refer to the crank shafts exhibited by Messrs. Marrel frères, of Gier, (France.) Of these one has three cranks placed 120° apart, and has a length of nearly 40 feet, the weight being 30,180 kilograms, or about 30 tons. Another is a four throw crank, say 27 feet in length and 12 inches in diameter.

Among the new applications of iron exhibited in the Exposition are the weldless bands made at the Bowling and Low Moor works,1 (England,) employed for uniting the cylindrical sections of steam boilers, covering the joints and strongly riveted on each side thereof, so not merely as to make a firm union, but greatly to stiffen the boiler when finished. The Bowling ring has a cross section like the letter U, with wide flanges, and seems better adapted to stiffen the boiler or flue, and to allow of expansion and contraction, than the flat ring made by the Low Moor works.

The one on exhibition is seven inches in total width, three-eighths thick, the arch in the middle rises two inches, and the width of the flanges is two and one-half inches. These bands would appear to be thoroughly well adapted to their purpose, and worthy of immediate adoption in our country.

CAST STEEL.

In cast steel, by whatsoever process produced, the same tending to large masses and difficult shapes was to be remarked. In advance of all other makers, the specimens exhibited by Krupp, of Essen, (Prussia,) were worthy of the highest admiration. The largest single piece of cast stell was a cylindrical ingot forged at one end into an octagonal shape, 56 inches in diameter, and weighing 40 tons. The grain of this ingot was exposed by the fracture of the forged end, and was uncommonly uniform and free from air bubbles. A piece had also been cut from the portion not forged, which showed at the place of fracture an equally uniform grain.

At the English exhibition of 1851, a cast steel ingot exhibited by Krupp, weighing two and a quarter tons, caused more astonishment than the ingot we have just described, because the world has since become familiar with metallic masses of enormous size, but the progress made in sixteen years in the production of cast steel is none the less marvellous, especially if considered in connection with the machinery necessary to produce and

For a description of the process of making iron at Low Moor, Bowling, and Farnley, the reader is referred to "Percy's Metallurgy of Iron and Steel," page 732.

work the ponderous ingots into shape, and the organization of the labor and skill required for their formation.

The establishment of Krupp occupies about 450 acres, of which onefourth are under roof. The number of men employed in the works is 8,000, besides which 2,000 more are employed in the coal mines, at the blast furnaces, and at the ore mines. The production of these works in 1866 was 61,000 tons, more than the entire production of cast steel in the world at the time of the first English exhibition. The value of this product was over $10,000,000 in currency. It was accomplished by means of 412 smelting, reverberatory, and cementing furnaces, 195 steam engines, ranging from 2 to 1,000 horse-power, 49 steam hammers, in the largest of which the hammer block weighs 50 tons,1 110 smiths' forges, 318 lathes, 111 planing machines, 61 cutting and shaping machines, 75 grinding machines, 26 special tools. 1,000 tons of coal are consumed daily in the manufacture of steel alone, and 120 steam boilers are in use evaporating 150,000 cubic feet of water daily. Fifteen miles of rail are laid in the works alone, and 6 locomotives and 150 cars are required for its use within the limits of the establishment.

In order to appreciate the eminent justice with which the grand prize of the Exposition was bestowed upon Frederick Krupp, it is not merely necessary to study these marvellous figures, but to consider that this establishment, by far the most extensive ever produced by the energy of man, and these processes, the most difficult ever attempted by his ingenuity, are the offspring of a single life, begun almost by the side of his father's humble forge, and rising through the various stages of poverty, trial, discouragement, and final success, to the very front of the industrial achievements of the world. Such an establishment, such results, and such a man, have special interest for the United States, where the natural resources of the country, the rapid progress of population and civilization, and the genius of our free institutions, all invite a generous emulation in order to equal, and in course of time even to surpass these magnificent achievements, which, if Krupp, the great captain of modern industry, had not lived in our day and generation, might well have been deemed impossible.

Among the other remarkable specimens exhibited by Krupp is a cast steel tire, rolled without weld, eight feet in diameter, a cast steel axle of crucible steel, with cast steel disk wheels, neither forged nor rolled, but cast directly into shape, weighing 1,623 pounds; a cast steel locomotive crank axle, with cast steel wheels six feet in diameter, weighing 3 tons 13 hundred weight; a cast steel junction ring of angular section, for uniting the courses of steam boilers, made without weld, eight feet in diameter, weighing 483 pounds; a cast steel double crank shaft for a screw steamer, 25 feet long, 14 inches in diameter, weighing (finished) 9 tons; forged under the 50-ton hammer from an ingot originally weighing 27 tons. And this is a proper place to note that cast steel crank shafts appear to

Krupp is now erecting a hammer of 120 tons.

be coming into general use, not merely for locomotive and stationary engines, but for the massive marine engines which are required for the steamers devoted to the business of transatlantic navigation. The experience with these cast steel crank shafts for marine engines does not appear to be sufficiently extensive to warrant any positive opinion as to the comparative value of cast steel and iron for the purpose, and it is possible that in cases where great resistance to torsion is required, iron will maintain its place. In any event the attention of engineers has been so called to this subject by the Exposition, that we may expect soon to have all doubts on this important subject removed.

The most striking object, however, in Krupp's exhibition, was the caststeel 1000-pounder rifled breech-loading gun, resting on a cast-steel carriage intended for the arming of coast batteries for the destruction of iron-plated ships. It consists of an inner tube, upon which are shrunk cast-steel rings. This tube was forged under the 50-ton hammer, from an ingot weighing 40 tons, but reduced in the process of manufacture to 20 tons by the loss of the sinking head, and by forging, turning, and boring. The cast-steel rings are three in number at the powder chamber, and two in number towards the muzzle portion of the gun. These rings weigh 30 tons in the aggregate, and were each manufactured from an ingot without welding. The total weight of the gun is 50 tons, the diameter of the bore is 14 inches, and the total length of the gun is 210 inches. In has 40 rifle grooves, in depth .15 inch, and the twist of the rifling diminishes from one turn in 980 inches to one turn in 1,014.4 inches; the weight of the solid shot is 1,212 pounds, and of the shell 1,080 pounds, and the weight of the latter is made up of the cast-steel shell, 834 pounds, the lead jacket, 220 pounds, and the bursting charge, 17 pounds; the charge of powder for the gun is from 110 to 130 pounds. The cannon reposes upon a steel carriage weighing 15 tons, and the two together work upon a turn-table weighing 25 tons. The turn-table was not exhibited for want of space, but it was stated that the gun-carriage slides smoothly upon the turn-table to the cheeks at the backstays at each discharge of the gun, and that two men can quickly and easily elevate, depress, and turn the gun so as to follow and cover with speed and certainty any vessel in motion. The price of the gun, which is understood to have been made for the Russian government, is £15,750 sterling, and of the carriage and turn-table £6,000, being about $150,000 in currency. Sixteen months of unremitted labor, by day and night, were expended upon its manufacture, and its transportation from the works to the Exposition required a car made entirely of steel and iron, weighing 24 tons, resting on 12 wheels.

It forms no part of the purpose of this report to institute a comparison between different systems of ordnance, or even to undertake to decide the relative value of cast and wrought iron and steel for the manufacture of guns, but it has been deemed best to give a somewhat elaborate description of this monster engine of war, in order to indicate the possi