Apr., 1916
T H E J O L ' R N A L OF I N D L S T R I A L A N D E N G I N E E R I N G C E E M I S T R Y
melting points give trouble from cracking after prolonged operation, and to this is t o he attributed our failure t o carry the test further. The Surface Combustion Company is at present working o n the problem of devising high refractories for these furnaces, and when these are available we hope t o resume this work and extend its scope. SUMMARY
A method for studying quantitatively the performance of a gas furnace and for determining the best conditions of operation bas been applied t o a surface combustion crucible furnace; data are given for the performance of this furnace. A temperature of 167j' C. ( 3 0 4 5 ~F.) was reached. I t has been shown t h a t complete combustion can be attained without excess of air, and t h a t a n excess of 20 per cent causes a lowering of furnace temperature of 100' C. (180' F.).
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these endeavors, t h e safety lamp remains to-day t h e universally used device for the quick testiug of mine atmospheres t o . determine their methane content. Many other devices have been exploited b u t the fact t h a t they are not widely used is proof t h a t they do not fulfill the needs. In working on the problem of gas detection in mines, the author endeavored t o develop something t h a t would be superior t o the safety lamp, as regards ruggedness, simplicity, weight and accuracy. I t is believed t h a t this has been accomplished. The apparatus is I O to 20 times more accurate than the safety lamp, is lighter in weight, is more rugged and fully as simple of operation. Percentages of methane in air as low as 0.10 per cent can be determined. A photograph of t h e device is shown a t Fig. I.
BYXBAUOP STAWDAEDS. W ~ s ~ ~ w r r o ~
DESCRIPTION OF A PORTABLE GAS DETECTOR' By GBOPOBA. BURXBLL) Received January 25. 1916
In this paper is given a description of a device for detecting combustible gases in most important use is for the detection of in mine air (fire-damp). but i t can also be
.fl portable air. I t s methane used for
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