width, that extends west from the lake shore, and is bounded north and south by a granitic district. They are developed in connection with great dikes and ridges of trap, which range east and west, and dip with the slates at a high angle toward the north. The ores also have the same direction and dip. Localities of them are of frequent occurrence for eighteen miles in a westerly direction from the point of their nearest approach to Lake Superior. A second range of the beds is found along the southern margin of the slate district; and about thirty miles back from the lake, where the slates extend south into Wisconsin, similar developments of ore accompany them to the Menomonee river and toward Green Bay. The quality of the ore found at different places varies according to the amount of quartz, jasper, hornblende, or feldspar that may be mixed with it; but enormous bodies are nearly pure ore, yielding from 68 to 70 per cent. of iron, and free from a trace even of manganese, sulphur, phosphorus, or titanium. A single ridge, traced for about six miles, rising to a maximum height ot fifty feet above its base, and spreading out to a width of one thousand feet, has been found to consist of great longitudinal bands of ore, much of which is of this perfectly pure character. Another ridge presents precipitous walls fifty feet high, composed in part of pure specular ore, fine grained, of imperfect slaty structure, and interspersed with minute crystals of magnetic oxide; and in part of these minute crystals alone. Another body of one thousand feet in width, and more than a mile long, forms a hill one hundred and eighty feet high, which is made up of alternate bands of pure, fine grained, steelgray peroxide of iron, and deep red jaspery ore-the layers generally less than a fourth of an inch in thickness, and curiously contorted. Their appearance is very beautiful in the almost vertical walls. On one of the head branches of the Esconaba is a cascade of thirty-seven feet in height, the ledge over which the water falls being a bed of peroxide of iron, intermixed with silicious matter. vessels down the lake. The business already amounts to more than 100,000 tons per annum, and is increasing very rapidly. The name Bay de Noquet and Marquette railroad suggests a southern terminus of this road on Green Bay, and when an outlet is opened in this direction, the production of iron ores will no doubt exceed that of any other region upon the globe. Large quantities will be reduced with charcoal in blast furnaces and bloomaries in the region itself; and when the forests in the vicinity of the works are cut off, the extensive timbered lands around Lake Michigan and Lake Huron will furnish inexhaustible supplies of fuel, which may be brought in vessels to the furnaces, as the pine wood from the forests around Chesapeake Bay has long been delivered to the furnaces on its western shore. Anthracite and bituminous coal will also be brought back as return cargoes by the vessels that carry the ores to the coal fields of Ohio and Pennsylvania. With its vast inland navigation and wonderful resources of iron and of copper also, the north-western portion of our country promises to be the scene of a more extended and active industry than has ever grown out of the mines of any part of the world. WISCONSIN.-Magnetic and specular ores. in bodies, somewhat resembling those of the region just described, are found in the extreme northern part of Wisconsin, upon what is known as the Penokie range, distant about 25 miles from Chegwomigon Bay, Lake Superior. Bad River and Montreal River drain this district. The ores, from their remoteness, are not soon likely to be of practical importance. Other immense bodies. of these ores, estimated to contain many millions of tons, are found on Black River, which empties into the Mississippi below St. Croix river, on the line of the Land Grant Branch railroad. A furnace has been built by a German company to work these mines. In the eastern part of Wisconsin the oolitic ore of the Clinton group is met with in Dodge and Washington counties, and again at Depere, seven miles south-east of Green Bay. In the For the supply of the few furnaces and town of Hubbard, Dodge county, forty miles bloomary establishments already in operation west from Lake Michigan, is the largest dein this district, and for the larger demands posit of this ore ever discovered. It spreads of distant localities, the ores are collected in a layer ten feet thick over 500 acres, and from open quarries, and from the loose is estimated to contain 27,000,000 tons. It masses lying around. A railroad affords the is in grains, like sand, of glistening red means of transporting them to Marquette, on color, staining the hands. Each grain has a the lake shore, whence they are shipped by minute nucleus of silex, around which the oxide of iron collected. The per-centage of iron ore and clay, 16 feet; sandstone, 34 metal is about fifty. This ore will probably feet; magnesian limestone, 7 inches; gray be worked near Milwaukee with Lake sandstone, 7 inches; "hard blue rock," 37 Superior ores, the La Crosse railroad, which feet; "pure iron ore," 5 feet; porphyritic passes by the locality, already affording the rock, 7 feet; iron ore 50 feet to the bottom. means of cheap transportation. The ore appears to be interstratified with MISSOURI. This state must be classed the silicious rocks with which it is associated among the first in the abundance of its iron in a similar manner to its occurrence at the ores, though up to this time comparatively other localities, and data are yet wanting to little has been done in the development of determine how much may exist in the hill its mines. The ores are exclusively hema-itself, as well as below it. Enough is seen to tites, and the magnetic and specular, and all justify any operations, however extensive, occur in the isolated district of silurian that depend merely upon continued supplies rocks-formations which almost everywhere of ore. In quality the ore is a very pure else in the western middle states are con- peroxide; it melts easily in the furnace, cealed beneath the more recent forma- making a strong forge pig, well adapted for tions. In the counties along the line of the bar iron and steel. Two charcoal furnaces Pacific railroad south-west branch, Prof. have been in operation for a number of Swallow, the state geologist, reports no less years, and up to the close of 1854 had prothan ninety localities of hematite. These duced 24,600 tons of iron. The flux is obare in Jefferson, Franklin, Crawford, Phelps, tained from the magnesian limestone, which Pulaski, Marion, Green, and other counties. spreads over the adjoining valley in horizonThe first attempts to melt iron in Missouri, tal strata. and probably in any state west of Ohio, were made in Washington county, in 1823 or 1824, and with the hematites of the locality were mixed magnetic ores from the Iron mountain. In Franklin county there is but one furnace, though on both sides of the Maramec are beds of hematite pipe ore, which cover hundreds of acres. The Iron mountain district is about sixty miles back from the Mississippi river (the nearest point on which is St. Genevieve), and extends from the Iron mountain in the south-east part of Washington county into Madison county. It includes three important localities of specular ore: the Iron Mountain, Pilot Knob, and Shepherd mountain. The first is a hill of gentle slopes, 228 feet high above its base, and covering about 500 acres a spur of the porphyritic and syenitic range on the east side of Bellevue valley. In its original state, as seen by the writer in 1841, it presented no appearance of rock in place, its surface was covered with a forest of oak, the trees thriving in a soil wholly composed of fragments of peroxide of iron, comminuted and coarse mixed together. Loose lumps of the ore were scattered around on every side but the north, and upon the top were loose blocks of many tons weight each. Mining operations, commenced in 1845, developed only loose ore closely packed with a little red clay. An Artesian well was afterward sunk to the depth of 152 feet. It passed through the following strata in succession: Pilot Knob is a conical hill of 580 feet height above its base, situated six miles south of the Iron mountain. Its sides are steep, and present bold ledges of hard, slaty, silicious rock, which lie inclined at an angle of 25° to 30° toward the south-west. Near the top the strata are more or less charged with the red peroxide of iron, and loose blocks of great size are seen scattered around, some of them pure ore, and some ore and rock mixed. At the height of 440 feet above the base, where the horizontal section of the mountain is equal to an area of fiftythree acres, a bed of ore is exposed to view on the north side, which extends 273 feet along its line of outcrop, and is from nineteen to twenty-four feet in thickness. It is included in the slaty rocks, and dips with them. Other similar beds are said to occur lower down the hill; and higher up others are met with to the very summit. peak of the mountain is a craggy knob of gray rocks of ore, rising sixty feet in height, and forming so conspicuous an object as to have suggested the name by which the hill is called. The ore is generally of more slaty structure than that of the Iron mountain, and some of it has a micaceous appearance. The quantity of very pure ore conveniently at hand is inexhaustible. The production of iron will be limited more for want of abundance of fuel than of ore. Charcoal, however, may be obtained in abundance for many years to come, and bituminous coal may also be The brought from the coal mines of Missouri and Illinois, as the ores also can be carried to the river to meet there the fuel. The local ity is already connected with St. Louis by a railroad. A blast furnace was built here in 1846, and another in 1855. A bloomary with six fires was started in 1850, and has produced blooms at an estimated cost of $30 per ton. Shepherd mountain, about a mile distant from the Pilot Knob toward the south-west, is composed of porphyritic rocks, which are penetrated with veins or dikes of both magnetic and specular ores. These run in various directions, and the ores they afford are of great purity. They are mined to work together with those of the Pilot Knob. The mountain covers about 800 acres, and rises to the height of 660 feet above its base. Other localities of these ores are also known, and the occurrence of specular ore is reported by the state geologists in several other counties, as Phelps, Crawford, Pulaski, La Clede, etc. In many parts of the United States and its territories iron is known to exist in great quantities. In Nebraska and Wyoming territory, near the line of the Union Pacific Railroad, large beds of iron ore of good quality are found, in proximity to extensive coal deposits, and these will be utilized for making rails of iron or steel for that great thoroughfare. In Kansas, Colorado, and New Mexico, are beds of specular and other ores in great profusion. The northern territories. as well as the Pacific States and territories, have abundant ores of the richest qualities, and coal enough and wood enough to melt them successfully. IRON MANUFACTURE. Iron is known in the arts chiefly in three forms-cast iron, steel, and wrought iron. The first is a combination of metallic iron, with from 1 to 5 or 5 per cent. of carbon; 14 the second is metallic iron combined with to 1 per cent. of carbon; and the third is metallic iron, free as may be from foreign substances. These differences of composition are accompanied with remarkable differences in the qualities of the metal, by which its usefulness is greatly multiplied. The three sorts are producible as desired directly from the ores, and they are also convertible one into the other; so that the methods of manufacture are numerous, and new processes are continually introduced. The production of wrought iron direct from the rich natural oxides, was until modern times the only method of obtaining the metal. Cast iron was unknown until the 15th century. Rude nations early learned the simple method of separating the oxygen from the ores by heating them in the midst of burning charcoal; the effect of which is to cause the oxygen to unite with the carbon in the form of carbonic acid or carbonic oxide gas, and escape, escape, leaving the iron free, and in a condition to be hammered at once into bars. The heat they could command in their small fires was insufficient to effect the combination of the iron, too, with the carbon, and produce the fusible compound known as cast iron. In modern times the great branch of the business is the production of pig metal or cast iron in blast furnaces; and this is afterward remelted and cast in moulds into the forms required, or it is converted into wrought iron to serve some of the innumerable uses of this kind of iron, or to be changed again into steel. In this order the principal branches of the manufacture will be noticed. The production of pig metal in blast furnaces is the most economical mode of separating iron from its ores, especially if these are not extremely rich. The process requiring little labor, except in charging the furnaces, and this being done in great part by laborsaving machines, it can be carried on upon an immense scale with the employment of few persons, and most of those ordinary laborers. The business, moreover, has been greatly simplified and its scale enlarged by the substitution of mineral coal for charcoal— the latter fuel, indeed, could never have been supplied to meet the modern demands of the manufacture. Blast furnaces are heavy structures of stone work, usually in pyramidal form, built upon a base of 30 to 45 feet square, and from 30 to 60 feet in height. The outer walls, constructed with immense solidity and firmly bound together, inclose a central cavity, which extends from top to bottom and is lined with large fire brick of the most refractory character, and specially adapted in their shapes to the required contour of the interior. The form of this cavity is circular in its horizontal section, and from the top goes on enlarging to the lower portion, where it begins to draw in by the walls changing their slope toward the centre. This forms what are called the boshes of the furnace the part which supports the great weight of the ores |