Altogether it was in a far from serene state of mind that I climbed down into the dinghy, and allowed Mr. Gow to row me back to the bank.
"Will you be over tomorrow, sir?" he asked, as he stood up in the boat ready to push off.
"I don't think so, I shall be rather busy the next two or three days." Then I paused a moment. "Keep your eyes open generally, Mr. Gow," I added; "and if any more gentlemen who have lost their way to Tilbury come and ask you the name of the Betty's owner, tell them she belongs to the Bishop of London."
He touched his cap quite gravely. "Yessir," he said. "Good-night, sir."
"Good-night, Mr. Gow," I replied, and scrambling up the bank, I set off on my return journey.
CHAPTER XVIII
A NEW CLUE TO AN OLD CRIME
It was exactly half-past ten on Tuesday morning when I sat down on the rough wooden bench in my workshop with a little gasp of relief and exhaustion. Before me, on the lead slab, was a small pile of dark brown powder, which an innocent stranger would in all probability have taken for finely ground coffee. It was not coffee, however; it was the fruit of four days and nights of about the most unremitting toil that any human being has ever accomplished. Unless I was wrong—utterly and hopelessly wrong—I had enough of the new explosive in front of me to blow this particular bit of marsh and salting into the middle of next week.
I leaned forward, and picking up a fistful, allowed it to trickle slowly through my fingers. The stuff was quite safe to handle; that was one of its beauties. I could have put a lighted match to it or thrown it on the fire without the faintest risk; the only possible method of releasing its appalling power being the explosion of a few grains of gunpowder or dynamite in its immediate vicinity. I had no intention of allowing that interesting event to occur until I had made certain necessary preparations.
I was still contemplating my handiwork with a sort of fatigued pride, when a sudden sound outside attracted my attention. Getting up and looking through the shed window, I discovered a telegraph-boy standing by the hut, apparently engaged in hunting for the bell.