Graphite, Plumbago, Black Lead.

Manufacturer and builder 9, 1878

Graphite is the proper name for what is contumely called Plumbago, or Black Lead. It is a unique mineral, useful for many and widely different purposes in the mechanical arts. The two purest forms of carbon are the diamond and graphite. The diamond is hard beyond every other substance; graphite is soft and smooth beyond every other substance, and these two substances are equally irdeniructible. The diamond outlasts everything else for given uses, and no graphite outlasts every other substance in resisting the action of the elements. It was utilized as a lubricator two hundred years ago. It has been mixed with clay for crucibles since the tenth century, but was not generally adopted till the foliated variety was utilized for the that time by the late Mr. Joseph Dixon, of Jersey City, in 1827, for the production of the "Dixon Crucibles," which have since become known in every part of the civilized werld.

Graphite was early used for crayons, and was found in use by the Aztecs when Cortex landed in Mexico. It is indispensable in the graphic arts, in the term of what are commonly called lead-pencils, which were first made in England from the granulated graphite taken front the celebrated Barrowdale mine; but after that mine was exhausted, the world was supplied with pencils made from graphite (or black lead) found in Bavaria and Bohemia, and purified for the purpose.

But recently the floe graphite found at Ticonderoga, in the State of New York, has been taken hold of for the Dixon American Graphite Pencils, by the Joseph Dixon Crucible Company, of Jersey City, N. J., and stencils produced that are claimed to be superior to any before known.

It is curious to note the progress of this graphite induetry. Formerly none but very common pencils were made in thie country; now the finest in the world are made here. In Europe they still work by hand in the production of fine pencils. At the Dixon works nearly every operation is by machinery, and it is most interesting to see pencils, all polished and finished, falling from a machine at the rate of 132 per minute, with no other hand-labor than that supplied by a little girl twelve years of age, who keeps the machine well furnished with material, and much of her time sits down, apparently amused at the rapid movements and perfect working of the combination of wheels and arms, belts, pulleys, rachets, and escapements, with a basket full of finished pencils, and they fall at last, and of the very finest grade, from the softest up to the hardest.

The Dixon pencils are very smooth, strong and pleasant to use, and wear longer than any pencils heretofure produced, besides being beautiful in style and finish.

The formation of graphite most common in the pure state is that of laminated crystals, elongated at right angles with the side of the vein, if it is not more than from four to six inches wide; but when the vein widens, te crystallization often radiates from numerous centers, while the whole formation is very beautiful. The foliated variety is equally valuable and more brilliant, but rare in any quantity; the acicular form of crystal is not apt to be as pure in the lump, but in useful for most purposes; the granulated variety, the purest of all, is of little use for crucibles, but, with suitable manipulation, produces the finest grades for electrotyping and fine lead.pencils, and is unequalled for lubricating. Pure graphite is absolutely free from grit, when pulverized and robbed between the fingers, and the polish produced in the same way is instantaneous and very bright, being like a darker shade of polished silver. It is also found mixed with iron, rhombspar, and other kinds of lime, the rock and earth in which the vein is carried, and many other foreign substances injurious for all the purposes for which pure graphite is needed. Lime, for instance, is fatal to graphite for making crucibles.

Graphite in the best known conductor of electricity, resists the action of acids or alkalies, is infusible at the highest hest, is not affected in the least by air, fire or water, and hence its great value as a preservative paint. Applied to iron-work, it prevents rust better than any paint yet used. Applied to tin roofs, it not only prevents rust, but is almost permanent, lasting far beyond any material. For roofs where the cistern water is used for drinking purposes, it is the only paint that is not injurous to health. Its natural color in paint is a slate, and shingle roofs painted with it have every appearance of slate, and by applying three good coats the roof will be perfect twenty years. The rain does not "wash" it in the least, the water going over it as if the roof were glazed, and for that reason it is applied to the bottom of racing yachts. The water rolls off as it would from a duck's back, without wetting the graphite, allowing the boats to glide freely through the water.

Our adjoined cut represents the most important graphite works its the world, those of the Dixon Company, located in Jersey City, N. J. The company own the mines, work them themselves, sell the raw stuck, prepare it for every known use, and manufacture it into every form into which it is now sold, namely, stove-polish, lead-pencils. paints, lubricators, axlegrease, for electrotypers, and a score of other uses.

The company keep a corps of trained correspondents, and any one in search of any information on the subject of Graphite and its uses, can be gratified by addressing them at their office in Jersey City.

A cable dispatch received from Paris says they have been awarded the Gold Modal.

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