The latter was obviously in the wrong, but, as a matter of fact, during his voyage across the Atlantic he had been chased by two enemy submarines and only by skilful seamanship and unceasing vigilance had succeeded in eluding them and saving his ship. He was, therefore, a trifle "nervy" and apt to suspect every indistinguishable floating object he met of being a submarine. Possibly, seen dimly through the fog, the _Knat_ looked something like a submarine awash and the captain of the _Cotswold_ had been justified in opening fire on her. Lawless, however, was ignorant of this, and the skipper's last taunt made him almost dance with rage. Fortunately, perhaps, another fog bank rolled up at this moment and the two vessels were again hidden from each other. For some moments Lawless growled to himself things which, had the captain of the _Cotswold_ heard them, might have produced a resumption of hostilities. Suddenly he gave vent to an exclamation: "I've got it!" "Got what?" inquired Trent. "An idea." "Extraordinary phenomenon; I'll have to make a note of it in the log. 'Seven p.m. Commanding Officer seized----'" "Don't try and be funny, it's too pathetic. What I'm going to do is to give that skipper the biggest shaking up he's ever had. If I don't get even with him you can call me Von Tirpitz and I'll turn the other cheek." "It sounds exciting." "You'll see," answered Lawless, and, leaving Trent in charge of the bridge, he disappeared down the companion ladder. A few minutes later a sound of hammering reached the Sub-Lieutenant's ears, and this went on, at intervals, for nearly a quarter of an hour. Presently Lawless emerged upon the after-deck, followed by two seamen carrying a barrel with what looked like a piece of stove-pipe protruding from it. "There," said Lawless, mounting the bridge again. "Isn't it a daisy?" "What is it--a patent incubator?" inquired Trent. "Pah! You've no imagination. That, my son, is an _idea_." "H'm! I always thought your ideas were pretty heavy, but----" "Shut up or I'll report you for insubordination." "Sorry, but I don't quite follow the drift of this ponderous idea of yours." "That's because yours is a stodgy, matter-of-fact, unromantic mind. But listen and I'll expound in words suitable to your infantine understanding. In the first place, I must tell you that one end of that barrel is weighted in such a manner that, when submerged in a suitable fluid, such as sea-water, it will float just below the surface. Secondly," continued Lawless, in the manner of one giving a lecture, "I would call your attention to a cylindrical object which, viewed at close range, somewhat resembles a drain-pipe. Nevertheless, my child, it is not a drain-pipe, but an invention of mine own constructed by the worthy artificer, yclept Bates. Lastly, a thin line of about six fathoms length, to the end of which is suspended a goodly lump of lead, is attached to the side of the said barrel."