"It looks like it certainly, but what he can be digging for I have no idea."
Presently the man was seen to raise a heavy weight on to his shoulders.
"It was a sack he had with him," Andre said, "and he has filled it with earth and stones."
Leigh did not reply. The mystery seemed to thicken, and he was unable to form any supposition, whatever, that would account for the man's proceedings. The latter carried his burden up to the cannon, then he laid it down, and took up some long tool and thrust it into the mouth of one of the cannon.
A light suddenly burst upon Leigh.
"The scoundrel is going to draw the charges," he said, "and fill up the cannon with the earth that he has brought up."
Andre would have leapt to his feet, as he uttered an exclamation of rage.
"Keep quiet!" Leigh said, authoritatively. "We have no evidence against him, yet. We must watch him a bit longer, before we interrupt him."
After two or three movements, the man was seen to draw something from the gun. This he laid on the ground, and then inserted the tool again.
"That is the powder," Leigh whispered, as something else was withdrawn from the gun; "there, you see, he is taking handfuls of earth from the sack, and shoving it into the mouth."