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after a sudden fall. In this neighbourhood, where a totally 
different system of working prevailed, explosions had mostly 
proceeded from an insufficient circulation of air in the goafs 
or exhausted parts, to dilute the gas as it escaped from the 
coal, and reduce it below the inflammable point. Of the 
usefulness of the barometer there could scarcely be two 
opinions. It was a singular fact, that the illiterate miners 
know instinctively that a south wind induces bad air in the 
pits. In this neighbourhood they imagine that the south wind 
blows through the whole strata, which inclines upwards to 
the south, and that the mine is thus filled with bad air. But 
however false in philosophy, being an observation founded on 
fact, it is practically of use to the miner, because, as a 
general rule, the south wind is accompanied by a low state 
of the barometer, and a sluggish circulation of air as a 
consequence. The barometer, by showing the pressure of 
the atmosphere, indicates the amount of escape of gas, and 
induces caution, on account of which it is a very necessary 
instrument. It was not necessary that the barometer should 
be kept in the pit at all. The engineman at the top is 
generally the best educated, and if under his charge any 
portentous change should occur, he could communicate 
instantaneously to all parts of the pit. 
Mr. Ward. — I do not see the least objection to that. 
Some further discussion was continued between Mr, 
Ward, Mr. Sorby, and Mr. James Haywood, analytical 
chemist. . 
The Chairman here called for the last communication 
announced for the meeting, which was 
ON SOME PHENOMENA AND EXPERIMENTS UPON CAPILLARY 
ATTRACTION. BY MR. T. J. PEARSALL, F.C.S., OP LEEDS. 
The leading object of Mr. Pearsall appeared to be to 
suggest the constant interference of mechanical forces of 
