The electrician obeyed him, and no sooner had he put the new lamp in the holder than the cellar was flooded with light. “Hullo!” he exclaimed. “The switch is on. I’ll swear I left it off on Saturday. Why, that’s queer! This isn’t the butt of an ordinary lamp at all. Looks to me like one of them electric detonator things, made to go into a lamp-socket. And it’s gone off, too. You can see where it’s blackened, sir.”

“Was the current on on Saturday?” asked Whyland, quickly.

“Yes, sir, I connected up in the morning,” replied the electrician. “Somebody must have put that thing in the lamp-holder, then turned the switch on. Well, that’s a rum go, and no mistake.”