the other in Nos. 3 and 4 of the year 1870. But I have not had the opportunity of seeing either of those articles, which are written in the Russian language.

DESCRIPTION OF THE MODE OF MANUFACTURE BY CAPTAIN N. MESHTCHERIN.

Toward the end of the year 1866, I was favored with a letter from a Russian mining engineer, Captain N. Meshtcherin, containing a much more circumstantial and satisfactory description of the mode of manufacturing the kind of sheet-iron which is the subject of these pages than any of the foregoing, and than any which, so far as I am aware, has hitherto been published. The description is illustrated by hand-sketches and prefaced with the following remarks, which I present with only a few slight verbal alterations :

"SIR: In your work, entitled 'Iron and Steel,' I noticed at p. 730, in the article on Russian Sheets, your remark that 'the method of their manufacture is,' you believe, kept rigidly secret, and the manufacture of such sheets is a desideratum in this country. Having, during about three years, been engaged in Siberia as a mining engineer of the Russian Government, and having been acquainted with that branch of iron industry, I thought that it would be of some interest to you to have information concerning the methods of procedure which are used in manufacturing such sheet-iron in Russia. The process is freely open to the inspection of all foreign travellers, as well as to natives of the country, but very little is known of it in Western Europe, chiefly because foreigners are ignorant of the Russian language, and also on account of the remoteness of the places of manufacture from Western Europe.

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"I beg to remain, yours, &c.,

N. MESHTCHERIN, "Russian Mining Engineer, Captain.

"68 Berners Street, Oxford Street, London,

15th November, 1866."

I may add that I had also the pleasure of making the author's personal acquaintance.

The manufacture of sheet-iron in Russia is chiefly confined to the ironworks on the eastern side of the Oural Mountains. The malleable iron, which is the subject of this manufacture, is derived from pig-iron, obtained by smelting the following ores with charcoal in cold-blast furnaces-namely, magnetite, carbonate of iron (sphæro siderite), and red and brown hæmatite. The conversion of the pig-iron into malleable iron is effected either in the charcoal-finery or in the puddling furnace.

The puddle-balls, intended for the manufacture of sheet-iron, are rolled into bars 5 inches wide and inch thick. The iron should be more crystalline than fibrous, and should contain sufficient carbon to render it more like steel than iron. machinery required consists of one or two pairs of rolls and two kinds of hammers. Reheating is conducted in furnaces of

The

particular construction. The rolls are driven by water-wheels, and should make not fewer than fifty revolutions a minute. The hammers are also put in motion by cams on the axles of water-wheels. The hammer-heads are of wrought-iron, with striking faces of steel. Each anvil consists of a solid block of white cast-iron. It is necessary that the hammers and anvils should be so made in order that they may have the requisite hardness, in default of which the surfaces of the sheets would not acquire sufficient brightness or polish. One kind of hammer is used for widening, and the other for smoothing, the sheets: both are raised to the height of 28 inches, and give from thirty-five to forty blows a minute.

Fig. 593. Side elevation of the first kind of Hammer for widening the sheets, of the Anvil, and of the Cam-wheel.

Fig. 594. End elevation of the Hammer-head and Anvil.

(The scale is given under Figs. 595 and 596. The numbers indicating dimensions are English feet and inches.)

Fig. 595. Side elevation of the second kind of Hammer for smoothing the sheets, of the Anvil, and of the Cam-wheel.

Fig. 596. End elevation of the Hammer-head and Anvil.

(The drawings for all the wood-cuts have been made by Mr. W. Prim.) The reheating furnace is represented in Figs. 597-8-9-600, and it is hoped that its construction will be clearly understood from a careful examination of those figures. Wood is the fuel used. It will be perceived that this furnace differs widely from the reheating or annealing furnaces employed in this country. The fireplace extends under the bed of the reheating chamber

from end to end, and the gaseous products of combustion enter that chamber through a series of five similar and equal openings in the bottom on each side.

Fig. 597. Longitudinal section of the Reheating Furnace on the line A B, Fig. 599. Fig. 598. Horizontal section on the line E F, Fig. 597.

In the construction of these furnaces there is one principle which must be rigidly observed, namely, the complete exclusion, as far as practicable, of free atmospheric air from the reheating chamber, in order to prevent superficial oxidation of the sheets. With this view, not only must the walls be made impervious to air, but the fire and ash-pit doors (d d), as well as the end door (e), must be made to fit as tight as possible. Tight fitting of the doors (d d) is secured by the arrangement shown in the figures.

The puddle-bars, 5 inches wide and inch thick, are cut into

pieces 29 inches long, which weigh about 15.35 lbs. avoirdupois (10 lbs.?-J. P.). These pieces are heated to redness and cross

Fig. 599. Transverse section on the line C D, Fig. 597.

Fig. 600. End elevation, where the sheets are put in.

THE FOLLOWING LETTERS, WITH DESCRIPTIVE REMARKS, APPLY TO FIGS. 597-8-9-600. a. Grate.

bbbb, Flues leading from the fireplace into the reheating chamber.

e, Chimney, which, in the original sketches, is shown as made of riveted ironplate. dd, Fire and Ash-pit Doors: they are made of cast-iron, and are hinged at the top; and to each door a hook is affixed, by which it may be conveniently opened.

e. Counterpoised Door.

f, Packet of Sheets, surrounded by logs of wood.

rolled into sheets about 29 inches square (see Fig. 601); and in order to become thus extended, they require to be passed through

Fig. 601.

The shaded part represents a piece of puddle-bar cut for rolling, and the dotted lines the form and dimensions of the resulting sheets.

the rolls about twelve or fourteen times. The sheets thus pro

duced are arranged in packets of three in each, heated to redness, and rolled, each packet passing through the rolls about ten times. But, just before rolling, the surface of each packet is cleaned with a wet broom, usually made of the green leaves of the silver-fir, and powdered charcoal is strewn between the sheets, in the manner shown in Fig. 602.

Fig. 602.

LIBRARY

UNIVERSITY OF

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Diagram, not to scale, showing the manner of strewing the charcoal-powder between the sheets.

The sheets obtained from this rolling are sheared to the dimensions of 28 inches by 56 inches. Each sheared sheet is brushed all over with a mixture of birch charcoal-powder and water, and then dried. The sheets, so coated with a thin layer of charcoal-powder, are arranged in packets containing from seventy to a hundred sheets each; and each packet is bound up in waste sheets, of which two are placed at the top and two at the bottom, as shown in Fig. 603. A single packet at a time Fig. 603.

is reheated, with logs of wood about 7 feet long placed round it, as represented in Figs. 598, 599, the object of which is to avoid, as far as possible, the presence of free oxygen in the reheating chamber. The gases and vapors evolved from heated wood contain combustible matter which would tend to protect the sheets from oxidation in the event of free oxygen finding its way into the reheating chamber.

The packet is heated slowly during five or six hours, after