The navy officer showed no surprise. It is a common enough incident for warnings of the same character. The mail of the navy department at Washington is always full of letters—some of them menacing in tone—from over-zealous apostles of "universal peace." Occasionally, too, a spy is unearthed serving in Uncle Sam's uniform. Such fellows are usually deported quietly and swiftly.

"I shall keep an eye on that sloop, sir, in that case," said the ensign, "but I'm afraid it will be difficult to do so before very long."

"How is that, Bulkley?"

The ensign waved his hand seaward. A hazy sort of atmosphere enveloped the horizon.

"Fog, eh?" commented the commander.

"Yes, sir. It will be all about us soon, or I'm mistaken. But look, sir, that aeroplane is almost above us."

"By George!—so it is. What's the aviator doing? He's signalling us. He's pointing downward, Bulkley, too."

"Looks as if he wanted to land on our decks, sir."

"It does. Hark! What's that he's shouting? Pshaw, I can't hear. Tell you what, Bulkley, order the aerial landing platform rigged at once. It ought not to take more than fifteen minutes."

"I'll have it done at once, sir."