The victim of the explosion, having recovered from his fright, stood giggling with nervousness. “My sand blew up, sir,” he said.
“Do you know what made it do so?” demanded Mr. Cary, sternly.
“No, sir. I was standing right here waiting for the thing to heat. It went off all of a sudden, right up in the air, and kept snappin’ all the way up.”
“And you know absolutely nothing more about it?”
“Not a thing!” answered Redfield, with evident honesty. “I wouldn’t blow myself up if I could help it.”
There seemed no reason to doubt the truth of Redfield’s statements; he was not only incapable of skilful dissembling, but also, as was generally known, a favorite target for heartless schoolboy pleasantry. Mr. Cary, therefore, asked no further questions, but turned off the gas from the burner, and dumping out the smoking sand poked it over in search of clews to the explosion—to the great delight of the half-dozen unworthies who were in the secret. Finding nothing, he bade Redfield start again with fresh sand, and returned to his desk.
A half-hour later Fluffy Dobbs’s mess blew up in the same way. This time the instructor, being hardly a dozen feet away, caught the full effect. He came directly to the smoking bath, but though his face blazed with indignation, he was too wise to embark on an interrogation which was unlikely to yield positive results.
“Don’t you think something is the matter with the sand, sir?” asked Wilmot, innocently. “Perhaps there’s nitre in it.”
“It isn’t likely.”
“Can this have anything to do with it?” suggested Wilmot, offering a charred bit of wood which he had picked up from the floor. The instructor took it, smelled of it, and shook his head. “I don’t know,” he said. “If these explosions are due to the sand, it is a remarkable occurrence. If they were deliberately caused, it is a very dangerous and culpable form of joke. We shall take only one experiment to-day. As soon as you have finished with that, you may go.”