440 KANSAS CITY REVIEW OF SCIENCE. 
an iron ring wrapped with the cord, which is simply put in place and nipped 
between two flanges, and, being unaffected by heat, lasts a very long time. 
We now come to an entirely different manufacture of asbestos, in which the 
rock, after being broken down and reduced to fluff, is pulped and formed by 
pressure into sheets from one-sixty-fourth to one-half inch in thickness. This mill, 
board, as it is called, is used for making joints not exposed to the action of 
moisture, such as for dry steam, air, and gas. When properly made and used 
with faced surfaces, this material affords the easiest and most cleanly method of 
making a joint, while, if the faces are previously painted over with boiled oil, the 
danger of having a troublesome leaky joint is reduced to a minimum. The board 
is easily cut to the desired size, and as no time is required for drying and setting, 
stean> can be turned on as soon as the bolts are screwed up. A much commoner 
and cheaper description, though it still possesses most of the essential qualities, is 
manufactured for fire-proofing floors and ceiHngs. It is made in sheets about 
one-thirty-second of an inch thick, and is applied in the simplest possible way, 
either above or below the joists. It is also used for lining the walls of wooden 
buildings, where, from its non-conducting and fire-proof qualities, it affords an 
immense protection in case of the outbreak of fire. As an insulator of electricity, 
asbestos in one form or another is greatly sought after. Millboard has for some 
time been used in the construction of dynamos, while cables and leads covered 
with plaited yarn have been adopted in many installations. The remaining uses 
of asbestos which we have to notice appear to be mainly in the production of 
fire-proof cement and putty, for which there is considerable demand for certain 
kinds of joints, and in the manufacture of fire- and acid-proof lumps, blocks, and 
bricks. The ordinary gas fire is familiar to everyone, and it will suffice to point 
out that asbestos enters largely into the composition of the artificial fuel upon 
which the success of the fire in a great measure depends. — Engineering and Min- 
ing Journal. 
GUNNISON, THE BONANZA COUNTY OF COLORADO. 
JOHN K. HALLOWELL. 
Mr. Hallowell closes his account of this county in the following enthusiastic 
terms : 
The foregoing represents as succinctly as possible a resume of what is the 
general characteristics in mineral wealth of this country, so that I have found in 
brief, that within a radius of seventy-five miles of Gunnison City, there are 2,000 
square miles of mineral lands, with more ore per square mile than was ever seen 
before in the world to know it. That the drainage of all but three points is 
towards a common center meeting at Gunnison ; that the whole country is readily 
accessible, having two competing railroads, narrow gauge, with a prospect of a 
third and broad gauge road within three years ; that branch Hues have been or 
