“Isn’t there any way of finding out?  Couldn’t you pump the Governor?”

“He is always very much on his guard, and is a taciturn man.  The moment the tunnel is finished I shall question him about some further electrical material, and then perhaps I may get a hint about the steamer.  I imagine she comes irregularly, so the only safe plan would be for us to make our attempt just after she had departed.”

“Would there be any chance of our finding a number of the military downstairs?”

“I don’t think so.  Now that they have their electric light they spend their time playing cards and drinking vodka.”

“Very well, Jack, that scheme seems reasonably feasible.  Now, get through your material to me, and issue your instructions.”

CHAPTER XIX

 “Stone walls do not A prison make”

In a very short time Drummond became as expert at the rock dissolving as was his friend.  He called it piffling slow work, but was nevertheless extremely industrious at it, although days and weeks and, as they suspected, months, passed before the hands of the two friends met in the center of the rock.  One lucky circumstance that favored them was the habit of the gaoler in visiting Drummond only once every four days.

The Lieutenant made his difficult passage, squeezing through the newly completed tunnel half an hour after a loaf had been set upon his table.  Jack knew that the steamer had recently departed, because, two days before, the Governor had sent for him, and had exhibited a quantity of material recently landed, among other things a number of electric bells and telephones which the Governor was going to have set up between himself and the others, and also between his room and that of the clerk and gaoler.  There were dry batteries, and primary batteries, and many odds and ends, which made Jack almost sorry he was leaving the place.

Heavy steps, muffled by the thickness of the door, sounded along the outer passage.

“Ready?” whispered Jack.  “Here they come.  Remember if you miss your first blow, we’re goners, you and I.”

Drummond made no reply, for the steps had come perilously near and he feared to be heard.  Noiselessly he crossed the cell and took up his position against the wall, just clear of the space that would be covered by the opening of the door.

At the same moment Jack switched off the light, leaving the room black.  Each of the two waiting prisoners could hear the other’s short breathing through the darkness.

On came the shuffling footsteps of the gaoler and lantern-bearer.  They had reached the door of Number One, had paused, had passed on and stopped in front of Number Two.

“Your cell!” whispered Jack, panic-stricken.  “And they weren’t due to look in on you for four days.  It’s all up!  They’ll discover the cell is empty and give the—­ Where are you going, man?” he broke off, as Drummond, leaving his place near the door, groped his way hurriedly along the wall.