Weekly journal-miner., 1911-07-05

!
 civilization in making parts of his
 weapons of defense as well as his
 apparel and habitation. He used both
 animal and vegetable fibers, and
 their utilization today forms the
 basis of many of the most impor-
 tant industries of mankind. But
 these organic fibers are easily destroy
 ed; they are ephemeral.
 The United States Geological Sur
 vey has just published an advance
 chapter from Contributions to Ee-
 Onomie Geology, 191O," on the i'm pOrtant asbestos deposits in the UnI-
 ted States, by J. s. Diller. Accord
 ing to Dr. Diller, asbestos is one of the most important minerals to hu- man welfare. The discovery of a mineral fiber in asbestos, which is ordinarily indestruetible, belongs to comparatively late period of eivili- zatiOn, although asbestos was used in the ancient pyre to preserve the roy 1 al ashes. Charlemagne is said to have had table cloth made of as- bestOs and used to clean it by throw | ing it into the fire to consume the dirt, thus Illustrating in a spectacular manner one of the most important properties of this mineral.
 The best grade of asbestos is beau tiful silky fiber with a high degree of flexibility, elasticity, and tensile strength. It can be spun into thread so fine as to run 225 yards to the ounce, and as it is ineombustible as well as noneonduetor of heat and elasticity and resistant to the &C., tiOn of most ordinary acids its field of application is large. The possibil- ities of the usefulness of asbestos are far from being fully appreciated not only by the general public but by manufacturers in search of mater ial for special purposes to which as- bestos may well be applied.
 Perhaps the most general use is to make fireproof cloth for theatre cur tains. In Germany it is used for | firemen's clothing. Everywhere in cold countries it is extensively en- ployed for furnace, boiler, and pipe | covering to prevent the loss of heat | Asbestos is a good insulator and ! whether steam or electricity is used | for power asbestos is one of the most important elements in the har- ness.
 The asbestos of commerce includes fibrous minerals of several species, but all may be included under am phibole and serpentine. Fibrous am- phibole is properly called asbestos, fibrous serpentine is chrysotile, and the especially fine silky form of both amphibole and serpentine is known as amianthus, but in the trade all are included under the general term asbestos.
 Like auifferous quartz and the or es of other precious metals, asbestos forms veins, but in some places where it is of low grade it makes up the whole mass of the eoun- try rock.
 There are three types of asbes- tOs-eross fiber, slip fiber, and mass fiber-distinguished by the form of aggregation.
 The most valuable asbestos fiber Q occurs in eross-fiber veins. The fib- er runs directly across the vein from $ side to side. Its length is thus limi- f ted by the width of the vein and ran- ( yes from one-sixteenth of an inch to T inches. For the most part the veins \ )f asbestos separate easily from the h country rock and when broken across ( expose the beautiful white fluffy as- I, oestos fiber with the sheen of silk. i, The highest grade of asbestos, about I Tn inch in length, is common in the n 'dolNAh O4 Odudud DuL HAS rot yet been produced in the United V states. It is worth about $275 a il on. The lower grades, ranging from V 100 down to less than sIO a ton, ei re much the more abundant in all r, sbestOs fields
 Slip fiber occurs along slipping lanes or faults and shows the direct on of the motion. Most of the slip lber asbestos is of low grade. 9; All asbestos is of secondary orig tf T and it may be derived by alter le ation from variety of rocks gen ta rally rich in Olivine or pyroxene. ti ome of it, however, is derived from ar npure limestone Rocks originally UT
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