When lightning acts with extraordinary violence, and breaks or shatters any thing, it is called a thunderbolt; which the vulgar, to fit it for such effects, suppose to be a hard body, and even a stone. But that we need not have recourse to a hard solid body to account for the effects commonly attributed to the thunderbolt, will be evident to any one who considers those of the pulvis fulminans and of gunpowder; and more especially the astonishing powers of electricity. It has been supposed that meteoric stones may have given rise to the notion of a thunderbolt. THUNDER-House. See Electricity.