It was Tuesday, shortly before dawn, when the rescuers pierced the first obstruction, only to find another and a worse break beyond.
A draft of air sucked through. Almost immediately the caps of the safety lamps showed blue. At the same time, the safety inspector called, "Back from the face, men! Back, all!"
He pointed to the little cage he had been holding.
The canaries had collapsed!
Carbon monoxide was pouring out, the deadly white damp, that kills as it strikes!
The hewers retreated, grumbling.
"We can stand it, with reliefs!" they declared.
But the Bureau man was adamant.
"Get back when you're told," he said shortly. "We'll get those men out all right. Bring the gas gang here!"
Then it was that the researches of the trained workers of the Bureau of Mines showed to their best advantage.