"Take care!" cried Bob, feeling some alarm at the risk his brother was running.
"All right, old man," returned Lawrence. "It's rather a fine view down the gorge from here. You'd better try it yourself when your head's mended."
He picked his way carefully over the somewhat uneven rock, and had gone three parts of the way round its circumference when he suddenly stood fixed, staring at something in front and a little below him.
"By George!" he ejaculated in an undertone. Then he lay flat on the summit of the rock, wriggled forward to the edge, until his head projected, and peered downwards.
"What is it?" asked Bob from his position several yards in the rear.
Lawrence did not answer until he had crawled backward and once more stood erect.
"I've solved the puzzle," he said. "The fellows have got courage at any rate, and must be as agile as monkeys. There's a rope hanging down from the last beam,--down the cliff into the water."
"A rope!"
"Yes, one of our stoutest, cleverly stained so that it's hardly distinguishable from the rock itself. I caught sight of something swaying, and it took me a few seconds to be sure what it was. Whoever it was that knocked you on the head--Tchigin very likely--he must have climbed the rope, twisted himself up on to the planks, and so got to the mine. It's a trick I shouldn't care to attempt."
"But how on earth did he get to the rope from the other side? He couldn't have forded, and the strongest swimmer couldn't get across with the torrent rushing down at something like eight miles an hour."