foxfire

Bioluminescence created by some types of fungus, particularly those growing on rotting wood.

The foxfire,—as the country people call it,—glowed hideously from the cold and matted bosom of the marsh; and, far from us, in the depths of darkness, the screech-owl sat upon his perch, brooding over the slimy pool, and whooping out a dismal curfew, that fell upon the ear like the cries of a tortured ghost.

Perhaps you've seen a foxfire in the woods. Well, in the dark, it looks like a live, burning coal; but when you go to it, and take it up, it's only a piece of rotten wood.

Wood exhibiting fungal bioluminescence; torchwood.

On the inside is fixed a Barometer, by which he can tell the depth he is under water; a Compass, by which he knows the course he steers. In the barometer and on the needles of the compass is fixed fox-fire, i.e. wood that gives light in the dark.

The navigator steered by a rudder, the tiller of which was passed through the back of the machine at a water joint, and in one side was fixed a small pocket compass, with two pieces of shining wood, (sometimes called foxfire,) crossed upon its north point, and a single piece upon the last point. In the night, when no light entered through the head, this compass thus lighted, was all that served to guide the helmsman in his course.