"Firedamp is almost without smell, and colorless.

It only really betrays its presence by an explosion." "Mr.Starr," said Simon Ford, "will you let me tell you what I have done?
Harry had once or twice observed something remarkable in his excursions to the west end of the mine.

Fire, which suddenly went out, sometimes appeared along the face of the rock or on the embankment of the further galleries.

How those flames were lighted, I could not and cannot say.

But they were evidently owing to the presence of fire-damp, and to me fire-damp means a vein of coal." "Did not these fires cause any explosion ?" asked the engineer quickly.
"Yes, little partial explosions," replied Ford, "such as I used to cause myself when I wished to ascertain the presence of fire-damp.