from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A loose, earthy deposit from water, found in the cavities or clefts of rocks, mostly white, but sometimes red or yellow, from a mixture of clay or ochre.
from the GNU version of the Collaborative International Dictionary of English
- n. A loose, earthy deposit from water, found in the cavities or clefts of rocks, mostly white, but sometimes red or yellow, from a mixture of clay or ocher.
from The Century Dictionary and Cyclopedia
- n. A loose earthy deposit formed by the infiltration of water and its solvent action on rock material.
The dry guhr can, of course, be examined, either qualitatively or quantitatively, for other mineral salts, such as carbonate of soda, &c. An actual analysis of dynamite No. 1 made by the author at Hayle gave --
In this case a small quantity of barium sulphate, say about 1 per cent., should be added to the guhr.
In a series of lead-lined tanks the guhr is weighed, placed in a tank, and the nitro - glycerine poured on to it.
A sample of the calcined guhr should not contain more than 0.5 per cent. of moisture and organic matter together.
The guhr is generally dried in a reverberatory muffle furnace.
A good guhr should absorb four times its weight of nitro-glycerine, and should then form a comparatively dry mixture.
After the guhr is dry it requires to be sifted and crushed.
If water is brought into contact with it, the nitro-glycerine is gradually displaced from the silica (guhr).
The time occupied in calcining will depend of course upon the quality of the guhr being operated upon.
The temperature should be sufficiently high to make the guhr red hot, or the organic matter will not be burnt off.
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