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of them, I was informed, are consumed by fire, caused, it is supposed, by spontaneous combustion, produced by oxidation of the pyrites in the coal.

The fire-clay beds contain the clay iron-stone, as on Coal creek, but no attempts have been made to ascertain its quantity or quality, and I could not anywhere see it in place. The dependence of the furnace is upon irregular deposits of a shelly hematite, locally known as “top-hill ore,” found scattered over the summits, ends, and slopes of many of the ridges which border South Boulder creek and Rock creek. These deposits extend to a depth of only one to three feet, and as they evidently do not form a part of the strata in the hills, it is impossible to make any estimate of the quantity of ore they will afford.

One can judge only from seeing numbers of acres thus covered that supplies may be obtained for one or more blast furnaces for several years; but extended observations would be necessary before positively asserting that large works could be supported from this source. The ore is found in pieces of all sizes, up to masses of half a ton weight, and large quantities of it are so fine that it would have to be collected for the furnace by screening.

There is scarcely any intermixture of foreign stony materials in these deposits. The quality of the ore is generally pretty good, though the larger masses are not so fine grained and pure as the smaller ore. · I should judge that an average of three tons would be required to make a ton of iron. The

ore is in excellent condition for the blast furnace, its long exposure at the surface having prepared it for smelting almost as thoroughly as if it had been roasted. Its unusual mode of occurrence, unconnected with the strata in the bills, was for some time a source of perplexity; and it seemed necessary to explain it correctly in order to judge better of the probability of the ore being found in large quantities in other places on the range of these forinations. On examining the country up to the base of the mountains, I discovered what I believe is the true explanation. At the distance of two and a half miles from the mines, the marginal ridge, already noticed, rises suddenly with a very steep face and dip of its strata, as represented in the section. The surface at its foot is covered with large, rounded boulders from the granite rocks of the mountains. Some, also, are of the red sandstones and conglomerates of the outer ridge. They decrease in size and numbers towards the east, indicating the movement in that direction of vast bodies of water or ice. These, together with the evidences of denudation I had observed further north-evidently not referable to the diluvial or drift formation-appeared to me as more strongly-marked evidences of glacial action than I had ever before seen. The extension of this over the hills near the furnace mast bave excavated the soft beds, of which they are in great part composed, and the light, clayey materials of the strata containing the iron ores being swept away by currents of water, these, by their weight, were left behind, and are now found spread over the surface of the hills. By long exposure they have been oxidized and converted from the clay iron-stone, or “blue-core ore," as it is here called, into the shelly hematite. Such a derivation of the ore, if correct, must itself make the quantity in any locality always uncertain. Found as it is, it is collected and delivered at the furnace at a cost of $3 per ton, making about $9 to the ton of iron.

Most of the materials required for constructing and supplying blast furnaces are found in great abundance at this locality. Sandetone of superior quality for building is quarried from extensive ledges that outcrop on the summit of a ridge within a few rods of the furnace. Blocks of it of uniform thickness are obtained of any desired size. It presents a fine apperance when cut, as seen in the small furnace, which is built of stone thus prepared. The fire-clay beds afford material for fire brick with which the furnace is lined, and stones, supposed to be sufficiently refractory, found near by, are used for the hearth and boshes of the furnace. An excellent limestome, both for mortar and flux, is found in a little ridge close at the foot of the marginal sandstone bill, along the

edge of the mountains, the position and form of which are indicated in the section. In the quarries just opened into this rock I was so fortunate as to find a few well-marked fossil shells, which will probably determine the age of this formation, as well as of what I believe to be the same limestone before described as occurring on both sides of the Black bills. Good clay for common brick is abundant throughout this region. It is largely worked about Denver, where bricks are sold for $8 to $10 per thousand. On Rock creek, a few miles from the furnace, at the crossing of the road to Denver, an establishment has been in operation for the manufacture of coarse articles of pottery. It is, however, now abandoned. The fuel with which it is intended to supply the furnace is charcoal, made from the pines of the mountains. The owners of the works, requiring only a moderate supply of good iron for their foundry and machineshop at Central City, are not disposed to try experiments at once with the mineral coal so near at hand. They estimate the cost of charcoal at the furnace at 10 cents per bushel. The wood is cut by contract at $1 per cord, which is about 3 cents to the bushel of coal. The coaling will cost 3 to 4 cents per bushel

, and the hauling the remainder. A difficulty is experienced in making charcoal in this region from the want of good turf for covering the pits. The light soil of the prairies or gravel of the mountains soon falls

through among the wood when this is fired. The furnace, owned by Messrs. Langford, Lee & Marshall, is a very small stack, of daily capacity of only 4 or 5 tons of pig iron. It is 20 feet square at base, 22 feet high, and 7 feet dianieter at the boshes. The hearth is 5 feet high and 18 inches diameter. It is intended to work the furnace with cold blast, and the consumption of charcoal will probably be from 250 to 300 busbels to the ton of iron. The cost of fuel in this case will be from $25 to $30, while that of ore, as above stated, may be rated at $9. The cost of the limestone for flux will probably not exceed 50 cents, and the remaining items of labor, repairs, &c., may be estimated at about $7. The total cost will probably be about $45 per ton of pig metal. In large establishments the expenses would be less, especially if the raw mineral coal could be substituted wholly or in part for the charcoal. The quantity of fuel, too, would be diminished by the use of the hot blast. The prairie country bordering the mountain toward the east, which presents the same geological and topographical features through Colorado to the north fork of the Platte river, will no doubt be found to afford, throughout this extent, similar resources for the support of a population dependent upon agricultural and manufacturing pursuits. Though deficient in forests, the lack of wood will be compensated by the abundant supplies of mineral coal, the existence of which has already been detected, even to the southern portions of Colorado. In that region there are also found springs of petroleum, and the manufacture of kerosene oil is already carried on to small extent, near Cañon City, for the supply of the Denver market.

T'he agricultural resources of the prairies are somewhat limited by the extreme dryness of the climate. Rain seldom falls, and were it not for the vever-failing supplies of water in the numerous streams running from the snowy central range of the Rocky mountains, the country would be an uninhabitable desert. Yet the soil is in great part fertile, warm and mellow, and abounds in gypsum and salts of soda, which appear upon the surface in the form of a white incrustation resembling frost. This is particularly abundant around the edges of dried-up ponds. The alkaline salts affect the waters of many of the wells, rendering them nauseous to the taste and unwholesome, and mixing with the dust of the roads, this is said to be in the summer season very injurious to the eyes of travellers. It is remarkable, that notwithstanding the want of rain, no great trouble is experienced over the plains for the want of water at the ranches and stations along

the roads. I crossed the Platte river at Fort Kearney in October, over its dry sandy bed, and yet the wells along the valley contained abundant water, and in general they were not twenty feet deep, their bottoms not reaching to the level of the stream. It is difficult to explain from whence these supplies are derived. The dryness of the soil renders irrigation necessary for its successful cultivation, and this is already practiced to a considerable extent in Colorado after the system of the Mexicans, which consists in the excavation of acequias or ditches, often several miles in length, by which the water of the streams taken out at an upper level is carried at this elevation past the farming lands, over which it is let out as occasion requires by tapping the acequias at any desired points. The cultivation is thus limited to lands lying below the level of the acequias; and such lands are met with of considerable extent along most of the streams, spreading out to great width, even before these have fairly emerged from the mountains. Very productive and extensive farms thus situated are seen running up among the basaltic hills on Clear creek, and similar improvements extend all along this stream to its mouth below Denver. The streams north of it, so far as and including the Cache à Poudre, afford the same advantages for cultivation of the soil, and along most of them the lands are occupied in continuous lines of farms. In the newness of the country, wbich has been occupied only two or three years, the crops are limited to a few of the most necessary articles. Flour being supplied to the Territory from the States and New Mexico, the cultivation of wheat is not so important as of the more bulky articles, which will not pay for transportation from such distances. Some wheat, however, is raised, and the crop is a successful one. But attention is chiefly directed to procuring the large supplies of hay, corn, oats, and vegetables, required by the numerous gold-mining population in the mountains. The bay being made from the wild prairie grass, its supply is limited only by the amount of labor employed in cutting and stacking it; still, owing to an overstock of it the previous year, the quantity put up in 1863 has proved too small for the demands of the country, increased as they are by the extraordinary accumulations of snow, which, covering the plains, cut off the herds of caitle and horses, with which the country is abundantly stocked, from their accustomed support by grazing during the winter. This, together with the obstructed condition of the roads, caused the price of hay in December last to rise to $105 per ton at the gold mines. Corn, which is a good crop, and may be raised to any extent along the streams, was worth at the same time nine or ten cents per pound. Potatoes are produced in abundance, as also onions, cabbages, and many other vegetables; but in this unpropitions season the prices of all these range very high. Onions are raised with scarcely any of the labor attending their cultivation in the States, yet they were from ten to twelve cents a pound. They grow so luxuriantly that a single one often weighs more than a pound. Such prices cannot be sustained in a favorable season, and particularly when the country is supplied with a more numerous agricultural population.

It is an important question, whether the cnltivation of these prairies is always to be limited to those portions capable of being irrigated only by the system now in use. The mountains, it appears, are abundantly provided with water, derived chiefly from the melting of the snows in the great Central Range. A large part of this, without doubt, penetrates under the stratified rocks, which on both sides dip away from the mountains. These waters probably flow iv underground channels far from the mountains, and if tapped by artesian wells sunk down to them, they might reasonably be expected to rise to the surface in neverfailing springs. The stratification of the country is certainly remarkably encouraging to such an enterprise; and another inducement to its prosecution would be the discovery of the mineral beds, whatever they may be, beneath the surface. This would be a certain and most economical method of determining the existence or non-existence of beds of coal in localities where it might be especially desirable to obtain this fuel. Artesian wells must at some time be exceedingly useful at Laramie plains, which are not so well watered as the country east of the mountains. These plains, hitherto entirely uncultivated, afford in places good pasturage, and a considerable amount of prairie-grass bay for the use of the overland stage line and of emigrants.

I left Colorado on the 19th of December, and being delayed several days in my journey through Iowa by the extreme severity of the winter season, arrived in New York on the 9th of January. Very respectfully, I am yours,

JAJES T. HODGE. New YORK, January 22, 1864.

New YORK, February 13, 1864. Dear Sir: I have carefully examined and analyzed the samples of coal that you brought from the Rocky mountains and placed in my hands. The specimens, according to the labels attached to them, are from two localities, viz: Coal creek and Boulder creek.

Those from the former place were taken, as you state, from a bed more than ten feet in thickness. The mineral has nearly the hardness of ordinary anthracite, but is much more brittle. The fragments are often cuboidal or rhomboidal, and in some of them a little amber was detected. The lustre is bright and shining. The coal does not stain the fingers. The powder is black when viewed in a heap, but when a thin film of it is spread upon a white surface it has a sliglit tint of brown-specific gravity, 1.29. When heated in a glass tube, the temperature of which is gradually raised to 400° or 5000 F., it gives off water, the last portions of which contain a little empyreumatic oil or tar. At a dull red heat it takes fire, burning wiih a bright yellow and smoking flame, emitting an odor between that of heated bituminous coal and that of imperfectly burning wood. Some of the fragments gave out a

ight odor of sulphur, which was traced to minute scales and spangles of iron pyrites scattered here and there among the lumps. Compared, however, with most bituminous coals, this mineral fuel is remarkably free from sulphur. When submitted to analysis, it yielded the following results : Water in a state of combination, or probably its elements, as ia dry wood...

20.00 Volatile matter, expelled at a red heat in the form of inflammable gases

19.30 Fixed carbon...

58. 70 Ash, consisting chiefly of oxide of iron, alumina, and a little silica . .

2.00

and vapors.

100.00

The ash is mostly reddish, but sometimes light gray. Another specimen contained only 16 per cent. of water.

The coal from Boulder creek, which occurs in a bed four feet thick, and in another ten feet, has a general resemblance to that from the other locality. It is, however, more dense, having a specific gravity of 1.4, and is less brittle, and the fracture is not so glosey. It contains also flakes of mineral charcoal scattered through the mass, and the proportions of its constituents differ considerably from those of the Coal Creek bed, it being a stronger fuel. It contains a little sulphur, like the other. The composition is as follows, viz: Water in a state of combination, or its elements ....

12.00 Volatile matter expelled at a red heat in the form of inflammable gases

26.00 Fixed carbon

59. 20 Ash, of a reddish color, or sometimes gray.

and vapors.

2. 80

100.00

From the characters and analyses of the specimens here described, it will be seen that the Rocky Mountain coal belongs to the class of lignites, and that it is not technically a bituminous coal, neither cannel nor an anthracite. Still, in common parlance, it will be regarded as coal. The geological character of the rocks in which the mineral is found will, I suppose, be given by yourself and Professor Hall. In calorific power the Rocky Mountain coal may be placed between dry wood and bituminous coal, and therefore it is a most valuable fuel, especially where bituminous coal and anthracite are not likely ever to be found, and firewood is difficult to procure. I see no reason why it may not be used for the smelting of iron and other ores. For locomotives it could be employed to advantage, with some modification of the fireplace. The ash is so small in quantity, and so light, that most of it would be carried off by the blast of the furnace. From my own trials I find that the coal burns freely in a small stove, making a hot and clear fire, and leaving no clinkers. The specimens that I have examined show a tendency to break up and crumble after they have been soaked with water and allowed to dry, so that it would be well to preserve the coal as much as possible from being wet by rain. The lumps that you brought home from your journey show no disposition to crumble in a dry place. In conclusion, I remark that the discovery of such extensive beds of a good mineral fiel is of the highest importance to the section of country in which they occur.

The iron is limonite, coinmonly known by the name of brown hematite or brown iron ore. It is a compact variety, and is certainly derived from carbonate of iron, some of which, in an unaltered state, is evident in one of the speci. mens. The carbonate will probably be found in larger proportion as the beds are worked further in beyond the reach of atmospheric influence. There is reason to believe that the iron obtained from this ore will be of good quality. Yours respectfully,

JOHN TORREY. J. T. HUDGE, Esq.,

APPENDIX No. 3.

REPORT OF F. M. CASE, CIVIL ENGINEER.

COLORADO TERRITORY,

Denrer, August 15, 1862. SIR : In submitting to you this report of my late instrumental reconnoissance of the Berthoud Pass and its castern approach, with the view of its being by you laid before the board of corporators of the Pacific railroad, I am aware that the facts which will be of real interest to practical railroad men are very ineagre; yet, as many misrepresentations have been made upon mere opinion, the few facts I have gleaned may be of interest to the board of corporators, of which you are a member.

I have had a connected line of levels run from the Platte river (at the upper bridge in Denver) to the summit of the pass, and two and three-fourth miles down Moses creek, on the Pacific slope.

From one mile below Empire City, a transit line has been run over the pass ; levels have been run up Clear creek a mile and a half above the mouth of Hoopes creek, opposite the pass, and also from Empire City to the low pass between Bard creek and the south fork of Clear creek. Between this low pass and Georgetown, one and three-fourth miles south, the relative elevations have been ascertained by barometric observations by Dr. Parry, a gentleman who is speading the summer near the range, making scientific explorations.

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