The younger man pointed.
"Do you ever fill up drill holes with cement ?" he asked.
"Not as I know of.

Why ?" "There 's one." Fairchild raised his gad and chipped away the softer surface of the rock, leaving a tubular protuberance of cement extending.

Harry stared.
"What the bloody 'ell ?" he conjectured.

"D' you suppose--" Then, with a sudden resolution: "Drill there! Gad a 'ole off to one side a bit and drill there.

It seems to me Sissie Larsen put a 'ole there or something--I can't remember.