He was, it appears, overpowered as the contraption failed to properly ignite.
Instinctively, we know it's not, but despair about how to turn the contraption off.
1825, western England dialect, origin obscure, perhaps from con(trive) + trap, or deception.
A contrivance or device; piece of machinery: What's this ugly contraption in the corner? (1820s+)