eriment. After waiting about an hour, Moodie,
whose practical experience of fire-damp in pits was greater than that of
either Stephenson or Wood, was requested to go into the place which had
thus been made foul; and, having done so, he returned, and told them that
the smell of the air was such, that if a lighted candle were now
introduced, an explosion must inevitably take place. He cautioned
Stephenson as to the danger both to themselves and to the pit, if the gas
took fire. But Stephenson declared his confidence in the safety of his
lamp, and, having lit the wick, he boldly proceeded with it towards the
explosive air. The others, more timid and doubtful, hung back when they
came within hearing of the blower; and apprehensive of the danger, they
retired into a safe place, out of sight of the lamp, which gradually
disappeared with its bearer in the recesses of the mine. {95}

Advancing to the place of danger, and entering within the fouled air, his
lighted lamp in hand, Stephenson held it finally out, in the full current
of the blower, and within a few inches of its mouth. Thus exposed, the
flame of the lamp at first increased, then flickered, and then went out;
but there was no explosion of the gas. Returning to his companions, who
were still at a distance, he told them what had occurred. Having now
acquired somewhat more confidence, they advanced with him to a point from
which they could observe him repeat his experiment, but still at a safe
distance. They saw that when the lighted lamp was held within the
explosive mixture, there was a great flame; the lamp became almost full
of fire; and then it smothered out. Again returning to his companions,
he relighted the lamp, and repeated the experiment several times with the
same result. At length Wood and Moodie ventured to advance close to the
fouled part of the pit; and, in making some of the later trials, Mr. Wood
himself held up the lighted lamp to the blower.

Before leaving the pit, Stephenson expressed his opinion that by an
alteration of the lamp which he then contemplated, he could make it burn
better; this was by a change in the slide through which the air was
admitted into the lower part, under the flame. After making some
experiments on the air collected at the blower, by bladders which were
mounted with tubes of various diameters, he satisfied himself that, when
the tube was reduced to a certain diameter, the foul air would not pass
through; and he