"Don't ever go closer to the brink of the cliffs than this, unless you have a line round you," cautioned Mr Trematon. "The ground might crumble under you, although there is far less probability of doing so here—where the rocks are composed of granite—than on the south-eastern coast of England, where the cliffs are of chalk and soft sandstone."
From where they stood the Scouts could see almost the whole extent of water between the Island and Beware Head, a sheet of deep blue sea interspersed with patches of pale green denoting sandy bottom between the weed-covered rocks. Long oily rollers came tumbling inshore with unfailing regularity, breaking with a smother of foam against the base of the headland.
"What makes those rollers, sir?" asked Baker. "There's very little wind, and farther out the sea is quite calm."
"It's called a ground-swell, and is said to be caused by a storm many miles out to sea. Their presence is also an indication of the approach of bad weather. I don't want to dishearten you, lads, but we must 'Be prepared' for all emergencies, and if we are I don't think our holiday will be any less enjoyable."
"There's a signal from the lighthouse, sir," announced Atherton.
"Now, then, signallers: what do you make of that?" asked the Scoutmaster, as a burst of flags fluttered from a staff rising from the gallery of the lighthouse.
"We can't make out, sir," replied Phillips and Neale. "They are not spelling anything."
"No, it is in code. The combination of those three flags means a message which we could only interpret if we had a signal-code book. One of those vessels 'made her number '—that is, has reported herself on first sighting a British signal-station—and the information will be telegraphed to Lloyd's. See, there's a keeper on the gallery. Watch him through your pocket telescope, Phillips, and when he looks this way tell Neale to call him up."
"What shall I semaphore, sir?" asked the Second of the "Wolves."
"Ask him for permission to visit the lighthouse," replied Mr Trematon. "Then, if he says yes, ask what day and what time will be convenient."