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American Oil-stones

American Oil-stones image
Parent Issue
Day
2
Month
September
Year
1885
Copyright
Public Domain
OCR Text

Wrltten íor the Coukier. It may not be gcnerally kuown, even among artisiuis usinf; oil-stones, Hint, instead of niporting tliem, American made oil-stones aro now exported largely to all foreign countries, including Australia, Egypt, Afnca, and South África. Prerious to about the year 1857, tb is country was alniost cntirely dependent upon Turkey and Hindostán for the supply; although Welsb stones and the Norway rag-stone were used to sotne extent. Turkey stone, however, Is rarely of uniform texture, while the Hindostán stone quickly lilis with meta), and the other kinds nanied, general have somc serious defect. All the Europeau varieties have, therefore, been euperseded, iu the markets of the world, by American oil-stones, as the latter not only possess far greater resisting properties, than those imported, but they are uniformily harder and finer, besides being more perfect; and for these reasons, they f ulfill, better than any otherc, the diiHcult requirenients of an oüstone. As infornmtiou regafding the rock - and the manufacture of oil-stones is rather meager - and, so far as known, confiued to one publication only of a technical character- the following parbulara, gathered by the wrlter trom a eadlng manufacturar of oil-stones in New York City, will not be deyoid of interest. Near the Hot Springs, Arkansas, is a ;ract of land about seveu miles square, wuere theso-called Novaculite, or "whetstone " rock, is found in apparently intïlaustible quanlities; and although the eculianties of tuis stone were known to lie Indiana of that state, as long ago as he beginning of the present century, yet t was not until about the year 1851, that lie rock was successfully utillzed for oiltones. There are two kinds of stone, the flner quality, known as Arkansas stoue, s seldom found more than eight inclies ong without ilaw, and as it usually ranges rom 10 to 60 pounds iu welghr, it is hipped froin the quarries mostly in bar els; while the coarser kind, called Washta stone, is obtained in blocks weighng from 100 to 4,500 pounds. Both lasses of Btone are quarried at a deptu of not less than ten feet below the sur'ace, m order to avoid thin quartz veins is much as posslble; quartz being harder ban the surrounding stone, the latter is worn away more rapidly, tlius leaving i he surface so rldgy, lumpy and uneven s to render the oil-stones imíit for use;!"hey are in the market to some extent, ¦ ut can be detected by dipping Uiein in water, which causes the spots and quartz eins to become plainly descernable. The Wasliita stone ís chiefly used by arpenters and wood-workers, while thé rkansas variety is particularly well adapted for the use of dentists, . rs of metal, jewelers and watcbmakers; Iso to sharpen unall delicate tools, as well as for surglcal and matliematical ' truinents, and for peiiknivcs and les. The cutting, pollshing and shnping of letones bas grown to be quite an iniortant industry, from a very small beiinning; 50,000 pounds per month beintt j ne amount cut by one manufacturer iu ïew York; but it is proper to state, ïowever, that this is more than is betnL one by any otlier three concerns, in the ame line put together - eitherat home or broad. Briefly described, the following Is the rocess employed iu cutting the gtone: 'he fragmenta of each are paeked upon ie bed of the saw-frame. The saws, which are of soft iron, have a i ng motion, and rise at the end of every troke and descend at the beginning of the I extstroke; and thesand and water wliicli re thrown upon them rlows down beween the saw-edges and the stone beeath, and the sand becoming imbedded i the metal cuts the stone as the saws move. Diamond pointed saws - which re generally used in cutting brown stone - would cut as much in twe"nty minutes s sand does In a day, but owing to the vonderful abraiding property of the Arlansas and Washita stone, the diamond oints are worn smooth after a few minites use; and so great is the strain that ie strongest saws set with diumonds ti o t nly doublé up, but the diamonds are requently either forced from their setings or broken - often both. in cuiiing wneei-[oneg, toe lower oto of the shaft is made gouge-shupeU so as to cut the core. The periphery of the wheel s cut by a soft iron, bent to forui an are of the circle it describes; the corner of the iron being rounded to permit the sand to flow under, the sime M t does with the straight saws. After being sawed into slab?, the stones are piled under another gang of sawx, liy wliich they are cut into propur widtlis; the ends are then cut in such a way as to avoid flaws and quartz veins. In cutting bevelcd surfaces the slab is held in an inclined position under the saw by means of piaster of Paiis. The finishing or polisliing of oil-stonos is done by pressing thestonc apon a ltrge horizontal cast-iron wheel or revolvipg tablp, covered with pand and water; this method being the same as that generally employed in polishing other kinds of stone. The usual size of an oil-stone Is eight inches long, two inches wide and ubout one and one-quartcr inches In thlckneM. Both the Washita and Aikansas stones are also mounted in mahogany cases, tor the use of amateurs, and are sold niostly in California and South America. Stone iiles are made jiointcd, knife-shapcil, cylindrical and in the sliape of triangular prisms.and are generally packed in smull paper boxes. Special toolsare also qwle for uce on hlghly tempered metáis - suoh as rifle barrelE and fine instrumento - being very desirable in obvUUnji waste of time in taking out and restoring the temper; to say nothlug of the risk Incurred by the opuration. Oil-stonea four inches long, one-hall inch wide, and requirlng 128 pieles to make the thickness of an inch, are sniiirmes linlshed; the labor alone, however, on such stone?, reaching as high a $liO per ]ound. And so rare is a large piece of Arkansas rod without flaw, that the cost of a wheel-stone nine Inches in diameter, would reach several hundred dollars

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Subjects
Ann Arbor Courier
Old News