What is "hercules powder"

Hercules \Her"cu*les\, n.

1. (Gr. Myth.) A hero, fabled to have been the son of Jupiter and Alcmena, and celebrated for great strength, esp. for the accomplishment of his twelve great tasks or ``labors.''

2. (Astron.) A constellation in the northern hemisphere, near Lyra.

   Hercules' beetle (Zo["o]l.), any species of Dynastes, an American genus of very large lamellicorn beetles, esp. Dynastes hercules of South America, which grows to a length of six inches.

   Hercules powder, an explosive containing nitroglycerin; -- used for blasting.