"Possibly."
"And when did you arrive?"
"At 3:32."
"How long had the fire been going when you arrived?"
"As nearly as I could estimate from the headway, about five minutes. Opinions varied a good deal on that point."
"Let us say five and add the three which elapsed before you heard the explosion. Then if there were a bomb in the study or library and its fuse were lighted at the start of the fire that fuse must have burned for eight minutes before it reached the powder."
"He's a genius," exclaimed Wye, but Ecks was sketching Shagarach's forehead and did not answer.
"I suppose so," said the fireman.
"A somewhat incombustible fuse. But if the fuse were not lighted at the start then presumably the fire started at the opposite end of the room and worked its way slowly toward the fuse?"
"Presumably."