What for?
I knew in an instant; I had read of such outrages, and it was to guard against them that we watched, and kept that dog.
I had hold of a large canister of gunpowder, and the soft cord wrapped around it was prepared fuse.
I comprehended too the horrible ingenuity of the scheme, which was to draw, by means of the wire, the canister of gunpowder on to the furnace, so that the fuse might catch fire, and that would give the miscreants who were engaged time to escape before the powder was fired and brought the chimney-shaft toppling down.
For a moment I trembled and felt ready to drop the canister, and run for my life.
Then I felt strong, for I knew that if I kept the canister in my hands the fuse could not touch the smouldering ashes and the plan would fail.
But how to do this without being heard by the men who must be on either side of the furnace-house.
It was easy enough; I had but to hold the canister high up above the fire, and pass it over till it was beyond the burning ashes and then let it continue its course to the other window.
It was a great risk, not of explosion, but of being heard; but with a curious feeling of reckless excitement upon me I held up the canister, stepping softly over the ash floor, and guiding the terrible machine on till the danger was passed.
Then stealing after it I climbed gently on to the broad bench beneath the clean window, and with my head just beneath it touched the wire, and waited till the canister touched my hand again.