It has recently been discovered that there bars are gradually spread out between smooth are extensive veins of a peculiar coal, called rolls, which are brought nearer together as block coal in Indiana, which is remarkably the metal grows thinner. The Russians have adapted to the production of the best iron. a method of giving to sheet iron a beautifully In its constituents and its working, it is very polished surface, and a pliability and duranearly a pure charcoal and containing nei- bility which no other people have been able ther sulphur nor phosphorus, it does not im- to imitate. All attempts that have been part to iron in the smelting process any in- made to learn the secret of this process have gredient which impairs its value. These entirely failed, and the business remains a veins of block coal are of great thickness, monopoly with the Russians. The nearest and extend widely over the central and imitation of this iron is produced at Pittssouthern part of the state. It has not thus burg, Pennsylvania, and several eastern estabfar been discovered in any other state. In- lishments, by what is called Wood's process. diana has no great variety of iron ores, but This consists in rolling the common sheet at her railroad facilities present, and prospec- a certain temperature while it is covered tive, for bringing the Missouri ores from with linseed oil. A very fine surface is thus Pilot Knob and Iron Mountain and the rich produced, but the pliability and toughness. hematitic ores from the Lake Superior re- of the Russian iron are wanting, even though gion in Michigan, are such that with this the sheets are often annealed in close vessels, excellent coal, her citizens can manufacture and the glaze and color are also inferior. the finest qualities of iron and steel at con- Sheet iron is now extensively prepared for siderably lower prices than they can be pro- roofing, and other uses requiring exposure to duced for, elsewhere. As a consequence the weather, by protecting its surface with a numerous furnaces have been erected in coating of zinc. This application is an 1870 and 1871, along the line of the block American invention, having been discovered coal veins, and many more are now going in 1827, by the late Prof. John W. Revere, up. The improved processes and new discov- of New York. In March, 1859, he exhibited, eries to which we have alluded, while they at a meeting of the Lyceum of Natural Hiswill materially reduce the cost of making tory, specimens of iron thus protected, which steel, do not, thus far, greatly lower the cost had been exposed for two years to the action of producing iron, except in Indiana, and of salt water without rusting. He recomhence the reduction of ten per cent. on iron mended it as a means of protecting the iron and iron manufactures in the new tariff of fastenings of ships, and introduced the proc1872, may impede the progress of this de-ess into Great Britain. Sheets thus coated sirable manufacture, now fast attaining to the first rank among our national productions. Though the total production of pig iron each year is now very definitely ascertained, there is more difficulty in learning the details of the other branches of iron manufacture. The rolling mills are really unceasing in numbers and in their aggregate production of rails both iron and steel, but the re-rolling of old rails is a large and yet very variable item in their annual amount of work, and it is difficult to ascertain with any considerable exactness what number of tons of new rails are produced by each mill. The aggregate product in 1871 was stated in round numbers at about 275,000 tons of iron and 180,000 tons of steel rails. This latter item will, undoubtedly, be largely increased during the present and coming are known as galvanized iron, though the iron is now coated with zinc by other means as well as by the galvanic current. One method, that of Mallet, is to place the sheets, after they are well cleaned by acid and scrubbed with emery and sand, in a saturated solution of hydrochlorate of zinc and sulphate of ammonia; and after this in a bath composed of 202 parts of mercury and 1,292 of zinc, to every ton weight of which a pound of potassium or sodium is added. The compound fuses at 680° Fahrenheit, and the zinc is immediately deposited upon the iron surface. Another method is to stir the sheets in a bath of melted zinc, the surface of which is covered with sal ammoniac. The use of heavy sheets or plates for building purposes is also a recent application of iron, that adds considerably to the demand. for the metal. The plates are stiffened by the fluting, or corrugating, which they receive in a powerful machine, and may be protected by a coating of zinc. Their prep aration is largely carried on in Philadelphia; and in the same works a great variety of other articles of malleable iron, for domestic and other uses, are similarly protected with zinc, as window shutters, water and gas pipes, coal scuttles, chains for pumps, bolts for ships' use, hoop iron, and telegraph and other wire. The production of the principal boiler-plate and sheet iron establishments of the United States is thus given for the year 1856: East of the Delaware there are but two mills, In E. Pennsylvania, on the Schuylkill and Sheet iron at the Sharon mill, Mercer Co. Penn. Tons. 550 21,218 9,649 500 2,000 38,289 A mill for boiler plate has been erected at St. Louis. IRON WIRE.—The uses of iron wire have greatly increased within a few years past. The telegraph has created a large demand for it; and with the demand the manufacture has been so much improved, especially in this country, that the wire has been found applicable to many purposes for which brass or copper wire was before required. It is prepared from small rods, which are passed through a succession of holes, of decreasing sizes, made in steel plates, the wire being annealed as often as may be necessary to prevent its becoming brittle. In this branch the American manufacturers have attained the highest perfection. The iron prepared from our magnetic and specular ore is unequalled in the combined qualities of strength and flexibility, and is used almost exclusively for purposes in which these qualities are essential. But where stiffness combined with strength is more important, Swedish and Norwegian iron also are used. Much of the iron wire now made is almost as pliable as copper wire, while its strength is about 50 per cent. greater. In Worcester, Mass., a large contract has been satisfactorily filled for No. 10 wire, one of the conditions of which was that the wire, when cold, might be tightly wound around another wire of the same size without cracking or becoming rough on the surface. Such wire is an ex cellent material for ropes, and considerable American iron is already required for this use, especially for suspension bridges. Wires are also used for fences, and are ingeniously woven into ornamental patterns. The socalled "netting fence," thus made, can be rolled up like a carpet. For heavier railing and fences, as for the front yards of houses, for balconies, window guards, etc., iron bars and rods are now worked into ornamental open designs, by powerfully crimping them and weaving them together like wires. NAILS-Among the multitude of other important applications of malleable iron, that of nail making is particularly worthy of notice, as being in the machine branch of itthe preparation of cut nails-entirely an American process. Our advance in this department is ascribed to the great demand for nails us in the construction of wooden among houses. In England, even into the present century, nails were wrought only by hand, employing a large population. In the vi cinity of Birmingham it was estimated that 60,000 persons were occupied wholly in nail making. Females and children, as well as men, worked in the shop, forging the nails upon anvils, from the "split iron rods" furnished for the purpose from the neighboring iron works. The contrast is very striking between their operations and those of the great establishments in Pennsylvania, consisting of the blast furnaces, in which the ores are converted into pig; of the puddling furnaces, in which this is made into wrought iron; of the rolling and slitting mills, by which the malleable iron is made into nailplates; and of the nail machines, which cut up the plates and turn them into nails-all going on consecutively under the same roof, and not allowing time for the iron to cool until it is in the finished state, and single establishments producing more nails than the greater part of the workshops of Birmingham fifty years ago. Public attention was directed to machine-made nails as long ago as 1810, by a report of the secretary of the treasury, in which he referred to the success already attained in their manufacture in Massachusetts. "Twenty years ago," he states, some men, now unknown, then in obscurity, began by cutting slices out of old hoops, and, by a common vice gripping these pieces, headed them with several strokes of the hammer. By progressive improvements, slitting mills were built, and the shears and the heading tools were perfected, yet much DUCTION IN 1856. In south New England, 12 mills, nails prin- Tons. labor and expense were requisite to make NAIL FACTORIES IN THE UNITED STAtes, and their pronails. In a little time, Jacob Perkins, Jonathan Ellis, and a few others, put into execution the thought of cutting and of heading nails by water; but being more intent upon their machinery than upon their pecuniary affairs, they were unable to prosecute the business. At different times other men have spent fortunes in improvements, and it may Troy, New York.. Rockaway, Boonton, New Jersey, nails and spikes.. Southern New Jersey. On the Schuylkill, 5 mills, about.. Middle Pennsylvania, 2 mills, about.. Maryland, 2 mills.. 25,000 4,000 8,250 4,167 9,000 2,600 2,000 2,155 1,075 Pittsburg, 14 mills, nails, spikes, rivets, tacks 14,195 Mahoning Co., N. E. Ohio, 1 mill. Total... 6,465 775 380 1,400 81,462 The number of nail machines employed in these mills was 2,645. be said with truth that more than a million of dollars have been expended; but at length these joint efforts are crowned with complete success, and we are now able to manu-Wheeling, 2 mills... facture, at about one-third of the expense that wrought nails can be manufactured for, nails which are superior to them for at least three-fourths of the purposes to which nails are applied, and for most of those purposes they are full as good. The machines made use of by Odiorne, those invented by Jona- A great variety of machines have been than Ellis, and a few others, present very devised for nail making, very ingenious in fine specimens of American genius." The their designs, and all too complicated for report then describes the peculiar character description. The iron is rolled out into bars of the cut nail-that it was used by northern for this manufacture, of 10 or 12 feet in carpenters without their having to bore a length, and wide enough to make three or hole to prevent its splitting the wood; that more strips, each one of which is as wide as it would penetrate harder wood than the the length of the nail it is to make. The wrought nail, etc. At that time, it states, cutting of these strips from the wider bars there were twelve rolling and slitting mills is the special work of the slitting mill, which in Massachusetts, chiefly employed in rolling is, in fact, but a branch of the rolling operanail plates, making nail rods, hoops, tires, tion, and carried on in conjunction with it. sheet iron, and copper, and turning out about The slitting machine consists of a pair of 3,500 tons, of which about 2,400 tons were rolls, one above the other, each having 5 or cut up into nails and brads. From that time 6 steel disks upon its axis, set as far apart as to the present the manufacture of nails by the width required for the nail-rod. Those machinery has been a profitable branch of upon one roll interlock with those upon the industry in the south-eastern part of Massa- other, so that when the wide bar is introchusetts, the iron and the coal being fur- duced it is pressed into the grooves above nished from the middle Atlantic states, and and below, and cut into as many strips as the nails, in great part, finding a market there are spaces between the disks. This at the south. The following table presents work is done with wonderful rapidity, several the number of nail mills in operation in bars being passed through at once. In the 1856. The smaller establishments are grad-nail factory each nail-making machine works ually going out of the business, and this is becoming more concentrated in the coal and iron regions, thus saving the cost of transportation in these heavy articles. The manufacturers of New England, however, ingeniously divert a part of their operations to the production of smaller articles, with which the cost of transportation is a less item in proportion to their value, such as tacks, rivets, screws, butts, wire, and numerous finished articles, the value of which consists more in the labor performed upon them and in the use of ingenious machinery than in the cost of the crude materials employed. upon one of these strips, or nail-rods, at a time, first clipping off a piece from the end presented to it, and immediately another, as the flat rod is turned over and the end is again presented to the cutter. The reason of turning it over for each successive cut is because the piece cut off for the nail is tapering, in order to make it a little wider at the end intended for the head than at the other, and thus, making the wider cut on alternate sides of the rod, this is regularly worked up into pieces of the proper shape. In the older operations a workman always sat in front of each machine, holding the |