The two Scouts promptly obeyed, wondering what was the reason for this exaggerated "leap-frog" posture.
"Now look at the sunset," continued Mr Trematon.
"The colours are ever so much brighter," exclaimed both lads, who, heads downwards, were observing the western sky between their outstretched legs. "They look too bright to be real."
"All the same they are natural colours. Stand up now, or the circulation of the blood towards your head will be obstructed. Yes, it has a peculiar effect. An artist friend of mine gave me the tip. By so doing one can see the vividness of an Italian sky in the corresponding misty atmosphere of our native land. But we must be moving."
Arriving at the edge of the cliff, Mr Trematon produced from his pocket a reel of black cotton. Cutting three or four twigs from a neighbouring bush, he set these in the ground so that they projected four inches from the surface. Their exposed ends he connected up by a length of cotton.
"If anybody comes here, the broken thread will give us proof," exclaimed the Scoutmaster. "I do not suggest that anyone will come, but if they do this is the best means of detecting their presence without giving them cause of suspicion."
"But the cotton only stretches for a distance of about ten feet, sir," remarked Phillips. "If anyone descended to the ledge from a point farther along the cliffs, this arrangement would not give any warning."
"I am afraid, Phillips, you didn't use your eyes sufficiently this afternoon. If you had you would have noticed that at all other places except this the cliffs overhang the ledge, and anyone being lowered would drop clear of the path leading to the caves. Hence it is reasonable to conclude that anybody knowing of the existence of the caves would naturally know the easiest means of gaining the ledge. Do you follow?"
"Yes, sir," answered the Second.
"Now let us be off, back to the camp. Those fellows are enjoying themselves to be sure. You can hear them quite plainly at this distance—it is another sign that stormy weather is near when sound travels clearly over a long distance."