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Updated: May 27, 2025
In short think as many things about the pencil as possible allowing the mind to pursue any associated by-paths, such as a consideration of the graphite of which the "lead" is made; the forest from which came the wood used in making the pencil; the history of pencils, and other implements used for writing, etc. In short exhaust the subject of "Pencils."
The graphite crucible serves as a plug for closing the end of the retort. It also forms a condensing chamber for the zinc fumes, and it also constitutes the negative electrode.
If a second edition was called for, the type had to be set again. Now, however, books are generally printed not from type, but from a copper model of the type. To make this, an impression of the page of type is made in wax and covered with graphite, which will conduct electricity. These moulds are hung in a bath of copper sulphate, where there are also large plates of copper.
We found some from one to two toises broad, full of small fasciculated crystals of rutile titanite. We sought in vain for cyanite, which we had discovered in some blocks near Maniquarez. Farther on the mica-state presents not veins, but little beds of graphite or carburetted iron. They are from two to three inches thick and have precisely the same direction and inclination as the rock.
It is a significant fact, and one which proves that the various kinds of coal which are found are nothing but stages begotten by different degrees of disentanglement of the contained gases, that where, as in some parts, a mass of basalt has come into contact with ordinary bituminous coal, the coal has assumed the character of anthracite, whilst the change has in some instances gone so far as to convert the anthracite into graphite.
Carbon occurs in inorganic nature in two crystalline forms, the diamond and black lead, or graphite, their physical differences evidently being the result of their different molecular structure. Graphite is a good conductor of heat and electricity, and the diamond is not. Carbon in the organic world, where it plays such an important part, is non-crystalline.
The Trampler pyrometer is based upon the difference in the coefficients of dilatation for iron and graphite, that of the latter being about two-thirds that of the former. There is an iron tube containing a stick of hard graphite. This is placed in the medium to be examined, and both lengthen under the heat, but the iron the most of the two.
I talked to Fred Hausinger, the maintenance boss; he doesn't like it, either." "Well, I'm no nuclear physicist," Melroy disclaimed, "but all that alpha stuff looks like a big chunk of Pu-239 left inside. What's Fred doing about it?" "Oh, poking around inside the reactor with telemetered scanners and remote-control equipment. When I left, he had a gang pulling out graphite blocks with RC-tongs.
A mile away there's an ample deposit of graphite carbon. Thus, there exists a complete local source of hydrogen, oxygen and carbon, ideal for synthesizing various hydrocarbonic chemicals or making complicated polyethylene materials such as stellene, so useful in space. Lead, too, is not very far off. Silicon is, of course, available everywhere.
Graphite, plumbago, or, as it is more commonly called, black-lead, which, we may say in passing, has nothing of lead about it at all, is best known in the shape of that very useful and cosmopolitan article, the black-lead pencil. This is even purer carbon than anthracite, not more than 5 per cent. of ash and other impurities being present.
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