because the great State of Tennessee wishes to save five or ten dollars a day-the pay of a few assistants.

We wish to be understood in this matter. We have in former numbers animadverted upon this parsimony of a great sovereign State which will squander thousands upon political profi gacy and begrudge a pittance-the smallest livelihood-to the science, the learning, the talent, which elucidates and eliminates the most valuable and important elements of that State's prosperity.

And while we reprehend parsimony, we shall always and with equal earnestness denounce extravagance in expenditures for such purposes, and in a future number shall give an exhibition of wicked wastefulness that will tell at least in one quarter. Our mining habits and cross-cuttings lead us in contact with all sorts of developments, and so long as we can hold a mining hammer we shall hammer away at all abnormal formations that protrude themselves in the paths of true science and practical knowledge, we care not whether the formation is that of a State or of stone.

The natural formations of Tennessee (unlike her political) are rich and varied, and resolvable from their topography and mineral constituents into seven divisions, and which singularly enough determine the three great political divisions of the State into West, Middle, and East Tennessee. The Unaka, or Eastern outlying division, comprises the group of wild mountain ridges flanking the base of the great Appalachian system and marks the line of demarcation of North Carolina. Many of these ridges are covered with open woods, affording unobstructed passage to the traveller for miles and the finest pasturage grounds. Some, again, arc entirely bald and locally termed "Balds," attaining in some points an elevation of 6,000 feet.

Next in order moving westward is the valley of East Tennessee, consisting of a series of small troughs and narrow straight parallel ridges, and very forcibly impressing the traveller with the notion that when he is crossing them from south-east to the north-west, that he is in a rolling country of "wave on wave succeeding."

Next in order is the Cumberland Table-land, comprising the Cumberland Mountains, and is in reality a table-land with welldefined rocky escarpments, and its sandstone top would furnish a noble highway from Kentucky to Alabama.

The Highland River of Middle Tennessee, [encircling] the Central Limestone Basin, the slopes of West Tennessee, and the Western outlier, the Mississippi Bottoms, make up the seven divisions. A particular analysis of each of these divisions requires more space than we can spare, but Prof. Safford has very neatly summed up the sketch: "Thus ends our brief sketch of the physical divisions of Tennessee. Mark the contrasts they afford! How unlike are the "Balds" of the Unaka, and the

Bottoms of the Mississippi; the fluted valley of the East, and the river-veined slope of the West; the wooded plains of the Tableland, and the rich rolling fields of our Central Basin. Surely there is no lack of marked variety in favored Tennessee."

Of the mineral wealth we may enumerate almost every element essential to the economics of American life. Iron ores, found under the most favorable associations, abound in the Limonite, Hematite, Dyestone, and Magnetic ores, scattered in inexhaustible profuseness.

Copper ore is found in Polk County, in the Unaka division, and when first found was supposed to be gold, but when ascertained to be only red copper ore was considered of no account. The sulphuret of lead (galena), carbonate of lead (cerusite), sulphuret of zinc (blende or black jack), carbonate and silicate of zinc (calamine), are all found in the State, but as yet little worked or valued. The sulphuret of silver has been found in the Cumberland mountains, but judging by the amount passing between the Legislature and State Geologist, we should think it a scarce article, and not easily parted.

The portion of the great Appalachian coal field is found underlying the Cumberland table-land before alluded to, and covers about 4,400 square miles. The varieties of coal are numerous, but most semi-bituminous and dry burning. Nearest the seat of greatest disturbance, (the eastern escarpment of the tableland,) the coals exhibit a spumose structure, and become more laminate towards the central and western portions of the track.

Tennessee has her marbles, and of beautiful texture, variety and color; specimens of some will be introduced in the new extension of the National Capitol. Green sand, marl, salt, nitre, alum, epsom salts, and peroxide of manganese, are found. "We have hundreds of caves and 'rockhouses in Tennessee, especially along the limestone slopes and in the gorges of the Cumberland table-land, which afford materials-nitrous earth-for the manufacture of nitre."

The efficient principle of the nitrous matter in the earth of these caves has undoubtedly been derived from the decomposi tion of animal matter brought in by wild animals during past ages, and as nitric acid has united with the lime and potash of the earth.

Hydraulic limestone, burrstone, roofing-slate and flagstones, are among the other useful products developed or classified by Prof. Safford's industry.

It is a matter of regret that each State Geological Corps finds it expedient to adopt its own nomenclature, and for local reasons generally. We concede the necessity of localizing by subdivi sions, when the details of a classification are required, but is it not too often the case that other views than merely illustrative ones enlarge divisions and classifications unnecessarily ? New

York, Pennsylvania, and Virginia, has each its system. In New York the upper silurian has been called Oneida, Medina, Clinton, Niagara, Onondaga, &c. groups; in Pennsylvania and Virginia, Formations IV, V, VI, and Levant series; in Ohio, Indiana and Kentucky, it is called Cliff limestone; in Tennessee Gray limestone or Harpeth Tennessee River group; in Iowa and Wisconsin, Formation III., Upper magnesian, &c. &c. Again the lower silurian has it synonyme in Stone River group and Nashville group.

The analogies of the New York and Tennesseean systems are such as to afford the conclusion, that the rocks of the whole silurian basin of Tennessee correspond to the lower silurian limestones of New York.

The synonima of the various systems are ascertained only by patient study, and by being kept constantly posted up with every new survey and exploration.

Our hope is that the Report of Prof. Safford will be read by those good citizens of Tennessee who know how to read, that they will thereby enlarge and enrich their hearts, and send to their Legislature delegates who can appreciate the great and varied blessings the State possesses in her scientific men and mineral resources, and by a liberal and judicious expenditure, prosecute with energy the exploration of her buried treasures, and give to her citizens and the world the benefit of her exploration in volumes that may alike instruct the mind and adorn the library as works of art.

ART. IV. THE IRON MANUFACTURE OF GREAT BRITAIN — THEORETICALLY AND PRACTICALLY CONSIDERED. By Wм. TRURAN, C. E. No. 7.

(Continued from page 391. Vol. 6.)
COAL.

THE Consumption of coal to smelt a ton of crude iron, varies with its richness in carbon and general quality; but is also influenced by the ore, flux, and blast. Measured by their richness in carbon, and estimating that a given quantity of the anthracite coal is capable of reducing 1,000 lbs. of iron, an equal quantity of the best of the Dowlais coals would reduce 954; Pontypool bituminous, 878; and Scotch, 835 lbs.

In no operation connected with the manufacture of iron, has there been a greater reduction made in the consumption of material than in the coal for smelting. The rigid economy of fuel practised in several Welsh works, has resulted in a saving of nearly two thirds of the quantity formerly considered necessary. In 1791, the consumption of coal to the ton of crude iron aver aged 6 tons, 6 cwts.; in 1821, it had diminished to 4 tons; and

in 1831, to 2 tons 5 cwts., which is nearly the quantity consumed at the present day.

The maximum consumption of coal for smelting an ore will depend on the quality and fusibility of the combined earths and the yield of iron. The silicious, from their infusible matrix, require the largest quantity of fuel in smelting; the red and hydrated hematites the next largest quantity; the calcareous require a lesser quantity; the argillaceous ores are smelted with comparative facility; but the least consumption of fuel takes place with the carbonaceous ores.

The presence of carbon, whether in chemical or mechanical combination, greatly increases the fusibility of ores. Silicious ores, which contain a portion of carbon, although abounding largely in silica, are smelted with greater facility, and produce a superior metal to those devoid of carbon. In several of the carbonates of the coal formations, silica is the predominating earth; but, owing to the carbon in combination, they are smelted with a comparatively low yield of coal. The quantity of carbon in the ore materially influences the consumption of fuel in smelting. If it is large, as in the carbonaceous ores, the yield is reduced nearly one half; and the fusibility of the metal is so great, that, with this reduced consumption of fuel, the production is augmented to nearly twice the quantity which it is possible to obtain of a similar quality, from the same furnace working on other descriptions of ore.

The consumption of fuel is affected by the richness of the ore, being greatest with the poorest ores; but when an ore contains more than 50 per cent. of metal (carbonaceous ores excepted), the consumption of fuel is not diminished below the quantity due to an ore of that richness. To produce carbonated iron from the richest ores, a quantity of shale is used, as compensation for the deficiency of earth in the ore, and to form a fluid cinder for the protection of the liquid iron in the hearth. The quantity of shale used increases with the percentage of metal in the ore, sufficient being added to reduce the average yield of the mixture to 50 or under, consequently, the consumption of fuel will be for an ore of this richness.

In smelting argillaceous ore, 50 cwts. of coal, containing 87 per cent. of carbon, is consumed for each ton of carbonated crude iron produced. This is nearly 21 lbs. of carbon to each lb. of iron; this proportion holds good with coals containing less carbon, the quantity of coal used being augmented, in the same ratio as its yield of carbon is diminished. But the circumstances which affect the carbonating powers of the fuel are numerous and of frequent occurrence.

With raw coal a given quantity of the anthracite species reduces the largest amount of carbonated iron. The semi-bituninous coals mined to the east of Merthyr Tydfil, the next largest

quantity. The Scotch is the coal most extensively used raw, but its carbonating powers are lower than either of the others.

It is with cokes as with coals--the harder and denser the coke, and the more concentrated the carbon, the greater the reducing power. A light, hollow, spongy looking coke exposes too great a surface to the action of the blast, and is consumed too quickly to yield a maximum effect; to maintain the requisite heat, the quantity is largely increased, and the consumption of carbon estimated on the amount in the raw coal, is twice or thrice the quantity with a superior coal.

The consumption of coal or coke will also depend on the hardness of the coal, and its cohesive strength to resist fracture in the blast furnace. Breakage in the furnace may occur either from the natural weakness of the coke, the great height of the furnace, the dense character of the ore, or with a soft coke, from its grinding against the ore and flux, producing a quantity of fine dust. It is only such pieces as reach the zone of fusion in a comparatively whole state that contribute to the maintenance of the high temperature. The small pieces and dust, are injurious to the action of the furnace, and do not contribute to the carbonization of the metal; as much carbon, then, as they may contain has to be added to the charge of unbroken coke. The presence of dust and small cokes is seen by the constant discharge of the tunnel head, and under the tymp, especially after casting.

The consumption of cokes is increased when they contain much water. A portion of the calorific power of the carbon is expended in vaporizing the water; and from the cooling of the surrounding materials by the heat thus rendered latent, the carbonating power is further diminished. If this water amounts to 12 per cent. by weight of the coke, not an unusual circumstance, the smelting power of the fuel is diminished; first, 12 per cent., the weight of the water; secondly, 12 per cent., the fuel consumed in vaporizing this water, and restoring the temperature of the materials; altogether, a diminution of 24 per cent. diminution of reducing power has to be met by an increased consumption. If 36 cwts. of dry cokes sufficed to produce carbonated crude iron, the consumption of wet coke will be 45.5 cwts. to produce the same degree of carbonization. But the consumption of wet coke is usually greater than this, which we account for by the fixation of oxygen, and the partial disintegration of the pieces by the escaping vapor.

This

The admission into the furnace of water, in any form, is attended with an increased consumption of fuel. If it enters with the ore, the increase in the quantity of fuel will be in proportion to the degree of saturation; but at all times, for the reasons giv en, be in excess of the quantity necessary to evaporate the

water.

Where water enters the furnace through the tuyere, in the