The timbers were numerous, and where one could see a short distance, ran on into the gloom in rows so closely spaced that they seemed continuous.
By and by Thirlwell found Scott looking up at a massive beam a few inches overhead.

The beam was not quite level, and the prop beneath one end had bent, while a threatening crack extended across the roof.
"We may have a bad fall here," Scott remarked.

"The prop's getting shaky and the pressure's pretty fierce.

I reckon we'd better shore her up as quick as we can.

It's lucky our lumber doesn't cost us much." Thirlwell examined the crack and thought it dangerous.