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chines Mr. Slater, on seeing them, pronounced quite worthless, as they undoubtedly were. The establishment of a small spinning-mill previous to 1793 is noticed in the account of the Byfield Factory, with the remark that the latter was, however, "the first regular factory."

This remark was probably made without due knowledge of the character of the first operations at Pawtucket, which, there is reason to believe, were at the highest point of perfection, both as to the performance of the machinery and the systematic details of management, to which the cotton manufacture had then reached in England, from one of the best factories, in which country they had been derived, of which Mr. Slater had been the principal manager up to the time of his departure, and to the perfection of which he was known to have largely contributed, by his skilful and systematic management.

Accordingly, the machines constructed by him and put in operation in Pawtucket in 1790, continued to be used without interruption, and without change of the original system, for nearly forty years, up to 1829, at which time the carding and spinning machines formed a part of an establishment of two thousand spindles, still existing in that village, called the "Old Mill." These machines were removed in the following year, the sale of Mr. Slater's interest taking place about that time.

It may be worth while to remark in this connection, that the impression generally prevalent, that the art of cotton spinning, as introduced into this country, was imperfect compared to that practised in England at the time, is erroneous, the fact being as stated above. The art of cotton spinning, with the best system of management then known, was introduced into this country by SLATER, in 1790, in all the perfection to which it had arrived in England at that time.

LAKE SUPERIOR MINES.

The "American Mining Journal" furnishes the latest, and probably the most authentic accounts from these mines. The Cliff mine, it seems, has never presented a better appearance than at the time of writing. A few days previous, twelve tons of copper were raised, the purest that had ever been taken from the mine. The Lac la Belle shows some improvement, but no particulars were given. The North American presents very encouraging prospects. The vein which is now worked, is represented as being twenty inches in width, and most of the lode yields good stamp work. Several small masses of copper have of late been obtained, averaging about 500 lbs. in weight. An engine and stamps had just been received, and would soon go into operation. The Copper Falls was also looking much better. Several small masses of copper had recently been raised from the lower level of one of the shafts, and the end of the drift was very promising. The product of the mine for the month of October was 4,458 lbs. of copper, estimated at 70 per cent; and 15,500 lbs., estimated at 15 per cent.

GOLD MINES IN VIRGINIA.

We have had the pleasure of conversing with a worthy gentleman from Louisa, says the Richmond Enquirer, in relation to some recent and extensive discoveries of immense deposites of gold in that country. A late discovery on the land of Mr. Boxley, conducted by Messrs. Rawlins and Fisher, is said to surpass the mines of South America. The place is called "Ally Cooper's," about two miles south-west of the north branch of the Pamunkey River. Mr. Rawlins, the lucky finder, washed in a small pan in a few hours (not exceeding seven) between three and four hundred pennyweights, (94 cents to the dwt.) Mr. F. has also discovered a very rich mine at Tinder's, with the prospect of an extensive deposite or vein. The mine of Mr. T. B. Harris, wrought by Mr. G. W. Fisher, continues to yield richly, and a few hands are collecting from $100 to $175 per day. A few days since we saw a large bar of gold, weighing about 500 dwts., from the White Walnut Mine, said to be exceedingly rich. We trust that with the vastly improved process of extracting the gold, the good county of Louisa may derive large benefits from the precious minerals diffused through the hitherto poor lands.

IRON FACTORIES IN KENTUCKY AND OHIO.

One of the most important neighborhoods for the production of iron on the Ohio River, is at a place called Ranging Rock. Within a circle of twenty miles there are 30 furnaces, 20 in Ohio and 10 in Kentucky. The produce of all combined amounts, when in full work, to 60,000 tons per annum.

METALLURGICAL TREATMENT OF GOLD ORES.

TESTING-EXTRACTION-SILICEOUS ORES-WASHING SAND-RICH ORES-PYRITOUS ORESPARTING-WET PARTING-QUARTATION, HOW PERFORMED.

The information embodied in the following paper, derived from Booth's " Encyclopedia of Chemistry," now published in parts by Carey & Hart, of Philadelphia, will not be deemed inapplicable to the times, when, as at present, our countrymen are in the successful search of the "golden sands” of California :—

Testing. The simplest method of testing auriferous sand is to wash over carefully and repeatedly with water, agitating the vessel, so that the gold particles may subside, and decanting the water, so as to carry off the fine sediment; then to pulverize the residue finely and wash again, repeating this operation until all the gangue is washed away and only gold remains. Vein gold, not containing pyrites, may be similarly treated, beginning with pulverization. If the ore abound in pyrites, the best method is to pulverize, roast thoroughly, wash over, pulverize and wash again, until the gangue is nearly all washed away. The former method gives a tolerably close analysis, but it is more accurate in both cases to wash the greater part of the gangue away, dissolve the residue in aqua regia by the aid of heat, evaporate to a small bulk to get rid of nitric acid by adding muriatic during evaporation, filter, add a clear solution of copperas to the clear solution, and after standing 24 hours, decant the greater part of the liquor with care from the precipitated gold, treat the residue by heat with muriatic acid, filter, wash, burn the filter, and weigh the pure gold. Not less than one or two pounds of poor ore should be employed, unless with a very sensitive balance; and if the gold do not precipitate at first, indicated by a momentary darkening of the solution, it will do so by standing. Very rich ores may be smelted directly with borax, or litharge, and in the latter case, a little charcoal will reduce a portion of the lead, which then takes up gold and silver and must be cupelled.

Extraction. A. Siliceous ores. 1. Washing sand. Auriferous sand is sometimes washed by hand, (in Africa, Hungary, &c.,) over an inclined plane with transverse parallel grooves, in the lowest of which the gold particles will be found mixed with sand; this should be pulverized and washed again to get pure gold. 2. Stamping ores. Sand and gravel are sometimes washed by machinery, whereby the pebble and gravel are removed by sifting, and the fine sand washed as above, by the machinery. But the sand and vein ore are more frequently stamped fine with water, and the fine sand and mud stirred with mercury to amalgamate the gold. The sand is washed off, the liquid amalgam pressed in bags of fine canvas or buckskin, and the solid amalgam remaining distilled, mercury passing over, and gold being left in a spongy state. Much mercury is lost if it be introduced into the stamping mill, and hence the employment of several mills, Chilian, Mexican, Tyrolesian bowls, &c., to amalgamate the gold contained in the sand after leaving the stampers. A considerable quantity of gold is lost by any one of these arrangements, and a better plan is to amalgamate in revolving barrels. About 6 dwt. gold to the bushel pays the cost of extraction in the United States.

B. Rich ores. These may be first powdered and washed, and the residue smelted with borax, litharge, or other fluxes, or they may be picked by hand, powdered, and directly smelted.

This

C. Pyritous ores. 1. These are sometimes pulverized finely, and washed over to a small very rich residue. The pyrites deposited from the water is washed again, once or twice, then exposed for months in heaps to the air, again ground and washed over. process is very imperfect. 2. The pyrites is first roasted, then ground, and amalgamated; or it is smelted to concentrate it, with or without previous roasting, the resulting stone ground and amalgamated. 3. The pyrites is smelted, with or without previous roasting, and the ground stone then fused with lead, which is eliquated and cupelled. If copper pyrites predominate, amalgamation is better than imbibition with lead and eliquation.

Parting. The gold obtained by any of these processes usually contains silver, which must be parted or separated, either in the dry or wet way. A. Dry parting. 1. With sulphur. The impure gold is fused and granulated in cold water, mixed with to of its weight of sulphur, kept heated for two hours or more without fusion, to form sulphuret of silver by cementation, then highly heated to fusion for one hour, to perfect the production of sulphuret and the separation of silver richer in gold; a little litharge is then added gradually, and the crucible slowly cooled, during which the greater part, 5-6 to 6-7, of the gold with silver collects at the bottom, (king,) and is separated by a hammer from the upper sulphuret of silver and lead, (called plachmal,) containing 1-6 to 1-7 of the gold; the plachmal is several times fused with litharge until all the gold is extracted. The kings

are fused with sulphur, &c., and when rich enough, subjected to quartation; the plachmal is fused with iron, forming sulphuret of iron and silver, which is refined.

2. With crude antimony. The alloy is fused in a glazed crucible with twice as much crude (sulphuret of) antimony, to which, when the content of silver is more than, a suitable quantity of sulphur is added. The sulphur unites with the silver, copper, &c., and the antimony with the gold, the latter alloy sinking to the bottom. If the gold contain much silver, this operation is repeated, with less antimony, after previous calcination. By calcination in a muffel, the antimony is driven off as oxide; the alley may be smelted with saltpetre, which is apt to occasion more loss of gold. The gold after calcination is fused with borax, saltpetre, and glass powder.

3. An obsolete method of parting consisted in stratifying the rolled or granulated alloy in a cement box with regal cement, composed of 4 pts. brickdust, 1 pt. common salt, and 1 pt. calcined copperas, and giving a slowly increasing heat for 18 to 24 hours. The sulphuric acid set from the vitriol disengaged from the salt muriatic acid, which formed chloride of silver and left a finer gold. The last was then cemented with saltpetre and common salt, whereby the remainder of the silver was extracted.

B. Wet parting. Parting by acids is superior to dry parting. 1. Sulphuric acid. This process, chiefly adopted in France, consists in heating the granulated alloy with oil of vitriol in cast-iron vessels, (or in less strong acid in platinum,) whereby sulphate of silver, copper, &c., is formed and dissolved, and gold left, which is again treated with sulphuric acid, washed, dried, and fused with saltpetre in black lead pots. This process is well adapted to large operations.

2. Quartation is performed by nitric acid, which, when free from muriatic or nitrous acid, dissolves silver and not gold, provided the alloy contains 3 pts. to 1 pt. gold. If it contain less silver, a portion must be added; if copper be present, the alloy must be cupelled. See ASSAY for the details of the operation. This process is only adapted for silver containing gold in nearly due proportion.

3. By aqua regia. Gold containing silver is treated with aqua regia made by mixing 1 pt. nitric acid of 32o B. (spec. grav. 1.28) and 4 pts, muriatic acid of 22° B. (= 1.178.) The granulated or laminated alloy is put into a flask, three or four times its weight of aqua regia poured over it, and digested until vapors cease to rise. The clear solution is poured off, the residue treated with 1 to 2 pts. aqua regia, this poured into the first, and the residue, chloride of silver, washed in a flask and then on a filter. A solution of copperas is then added to the gold solution, whereby metallic gold is precipitated, which is digested with dilute muriatic acid, washed, and fused with borax and saltpetre.

COST OF MANUFACTURING COTTON GOODS.*

The work, the title of which will be found at the foot of this page, embraces a collection of the most useful calculations for the Mechanic and Manufacturer; and it seems to us that its publication is particularly well timed, as efforts are being made to establish various branches of manufactures in the southern and western States, which will, we have no doubt, prove successful, and highly advantageous to the interests of the people in the region of the "sunny South and the fertile West."

Mr. Leonard's calculations on motive power are condensed and arranged in as comprehensive a mode as possible, so that the mechanic can obtain the solution of any problem, simply by referring to the tables. The information relating to water and steam power, and their application to various branches of manufacture, appears to be quite complete. The table which contains the calculated power of belts is, we are informed by the author, the first of the kind which has been published. That portion of the work relating to cotton manufacturing is particularly full, exhibiting the cost of machinery, and of building factories; and the tables, in showing the cost per yard of manufacturing different styles of goods from different prices of cotton, are predicated upon the yearly results of a large number of factories. It required no small amount of labor to perfect the work; its design, however, proposes a plan of arranging calculations which cannot fail to be of great practical utility to the mechanic and manufacturer..

* The Mechanical Principia; containing all the various calculations on Water and Steam Power, and on the different kinds of Machinery used in Manufacturing; with Tables showing the cost of Manufacturing different Styles of Goods. By CHARLES ELLREDGE LEONARD. 12mo., pp. 197. New York: Leavitt, Trow, & Co.

ANALYSIS OF CALIFORNIA GOLD AND FORMATION OF THE MINES.

The following letter, from Professor Horsford, of Harvard University, was originally published in the Mercantile Journal of Boston. It will be read with interest, not only for the statement of the analysis of a specimen of the California gold recently received in that city, but also for the plausible theory therein advanced in relation to the formation of the gold fields :

Cambridge, December 14th, 1848.

MY DEAR SIR:-The California gold, from Feather River, received by Mr. Eaton, has been analyzed, and contains gold, silver, iron, and a trace of copper.

It has been carefully examined for platinum, tellurium, and any other bodies that might have been present, but without success.

In constitution it corresponds with fifty other specimens, whose analysis are on record. The iron and copper are present in invariably small quantities, while the proportion of silver ranges from 1 per cent to more than 70.

The very small quantity employed in the analysis, (about 250 millegrammes,) and the four separate determinations, rendered a slight loss inevitable. The gold might safely be stated a little higher :

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You will remember that the specimen sent for analysis was in scales. The average weight of them may be of interest to you:

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The occurrence in this form, while the gold in the rock from which the scales have been derived, is, without doubt, in California as in Mexico and Virginia, in granules, of more or less approximation to a spherical form, presents an inquiry of much interest, viz: How have the granules become flattened?

From what I have seen of glacial action in the Alps, and of its effects in this vicinity, and in various other sections of northern United States, I am strongly persuaded that the flattening of the granules has been caused by the transit of glaciers, with their masses of imbedded boulders and gravel, over the rock containing the gold. It accomplished at one stroke the reduction of the rock to gravel and sand, and of the granules to plates. This will explain how, in the alluvial plain, here and there richer veins of the metal occur. The paths of ancient moraines, or rivers parallel to the direction of the glaciers, would contain more; the intervening spaces now filled up with lighter materials, spread about by subsequent simple aqueous agency, would contain less of gold.

This consideration may furnish a suggestion as to the direction from a point found to be rich in metal, in which labor will probably be rewarded. If the deposits have been made by glacial agency operating at right angles to the direction of the coast, excavation in a direction north and south must cross their course; excavation in a direction from or towards the mountain range would be either upon or parallel to their course, and would cross only the terminal morains. I am, very truly, yours, EBEN. N. HORSFORD.

DISCOVERY OF GOLD IN CANADA.

Professor B. Silliman, Jr., has published a brief account of his examination of masses of gold found in the valley of the Chaudiere, Canada. The lumps are worn smooth, as is usual in alluvial gold, but fragments of quartzose gangue conld still be detected in some of them. They were firmly imbedded in what appeared to be slate, but which is probably a concrete of detritus cemented by oxide of iron. Chromic iron, titaniferous iron, serpentine, spinel rutile, and talcose rocks, remind us very strongly of the mineralogical characters of the Russian gold region; and their occurrence with the gold in Canada certainly affords favorable grounds for the hope that this may become a rich auriferous region. As yet, no excavations have been made on any scale of magnitude sufficient to warrant an opinion of the actual wealth of the deposit. A few tons of gravel have, however, been washed in a rude way with the Berks rocker, which have yielded about $4 of gold to the ton of gravel.

PORTSMOUTH STEAM COTTON FACTORY.

A correspondent of the "Chronotype," who recently visited this establishment, furnishes the following statement, as the result of his investigation:

The capital stock of this company, per charter, is $1,000,000. Amount actually taken, $530,000. This establishment was erected for the manufacture of the finer cotton fab. rics. The middle section of the mill, 200 feet long by 70 feet wide, and six stories high, is now built, and contains over 21,000 spindles, all hand mules, and 500 looms; manufacturing lawns, organdines, plaid muslins, chambreys and ginghams, from yarns varying from No. 70 to 110. The product of the looms is some 23 yards each per day. Should the results of this section of the establishment prove satisfactory, (of which there appears to be no doubt,) two wings, 150 by 70 feet, and five stories high, will be erected, which will swell the concern to 50,000 spindles, 1,000 looms, and involve a capital of $1,000,000. The whole appropriated to the production of fine cotton fabrics.

The number of girls employed in the mill at present is about 380. They are very healthy looking, much more so than in any other establishment of the kind I ever visited. Some of them are very beautiful to look at, intelligent to converse with, and dress like republican queens, which all of them are. The neatness which seems to characterize their persons, their modest demeanor, their close attention to business in the mill, and lady-like appearance when out-at lecture, in the ball-room, concert, or private circleis the cause of universal remark, and what none with eyes can avoid observing and admiring.

In point of steam power this company have made an important discovery, which economists will be glad to learn. They commenced operations about two years and a half ago. They had employed one of Hill & Andrews' powerful horizontal engines of 24 inch cylinder and 4 feet stroke. They used the same until last August, when the company became dissatisfied with it, and substituted one of Tufts' largest size stationary engines, of the same size cylinder and stroke. The former consumed over eight tons of coal per day. Notwithstanding this extravagant consumption the machinery worked slowly; the operatives complained, particularly those who worked by the piece, about slow and unsteady speed. Tufts' engine has been in operation since August, and given general satisfaction. There have been no complaints whatever. The machinery works smooth, steadier, and quicker. But the most important fact with reference to these two engines is the cost of running. Where Hill & Andrews' engine requires over 8 tons of coal per day, Tufts' consumes less than 4 tons, and sufficient heat is also obtained to warm the whole building. This astonishing difference seems hardly credible, but figures wont lie, when made by disinterested parties. This fact, with reference to coal, was furnished me by the fireman of both engines, whose business is to economize for the company, but not to give preference to engine builders. The difference is attributed in part to a change in the mode of heating up. Slow combustion has proved more economical than quick, unsteady fires. But the main difference lies in the construction of valves. I was forcibly struck with the uncommon neatness and great beauty of this ponderous and wonderful construction. It is the largest horizontal engine ever manufactured by Tufts, except the one used in Forbes' propeller, which plies Boston harbor as a tow-boat.

Great neatness and regularity characterize every apartment of this monster establishment. More time is allowed the operatives for meals than at any other establishment with which I have yet become acquainted. The operatives are highly spoken of by the town's people, which I am sorry to say is not always the case in other manufacturing places.

MAMMOTH SCYTHE MANUFACTORY IN MAINE.

At North Wayne, in Maine, is situated the scythe manufacturing establishment of Reuben B. Dunn, Esq., the largest of the kind in the world. The establishment consists, besides warehouses, furnishing shops, &c., of three principal buildings for manufacturing, two of which are one hundred and forty-four feet each in length. In these, and in departments connected with the establishment, are employed about one hundred men, many of whom have families settled at the place. A flourishing village has grown up within a few years, and is rapidly increasing. Twelve thousand dozen scythes are annually manufactured, to produce which are required 450,000 lbs. of iron, 75,000 lbs. of steel, 1,200 tons of hard coal, 10,000 bushels of charcoal, 100 tons of grindstones, and half a ton of borax. The last article is used in the process of welding. The establishment is to be enlarged so as to turn out 17,000 dozen scythes annually.

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