Although Bob had fully determined to turn the brig toward the coast on this day, there was no change in her course at noon, and for a very good reason. Before daylight the breeze had died away entirely, and at nine o'clock the Bonita was rising and falling on the glassy ocean with not air enough stirring to lift the narrow thread of blue bunting at the main-truck.
The involuntary crew had spread the yawl's sail from the house to the starboard rail as an awning, for the heat in the cabin was too great to admit of their remaining below, and under this all sought shelter from the sun's fervent rays.
Bob found a reasonably large stock of tobacco among the Bonita's stores, and with this and a short black pipe he occupied himself during the hours of enforced idleness, while the boys thought of home and the loved ones whom they might never see again. The seconds came and went until the sun was directly overhead, and the old sailor had but just settled down for a noonday nap when all four sprang to their feet in alarm, as the deafening crush of an explosion was heard.
The brig quivered from stem to stern as if from the effects of a torpedo beneath her keel, and the fore hatch was flung high in the air while a dense cloud of what appeared to be smoke arose from the hold.
Astonishment and fear rendered the younger members of the crew incapable either of speech or movement, and they might have remained staring stupidly forward an indefinite length of time if Bob had not shouted, excitedly:
"It's a case of fire, lads! Jump to it for what provisions an' water can be got out in a hurry! There's no time to be lost if we want to leave, for most likely the hold is one mass of flame."
These hurriedly-spoken commands aroused the boys from their stupefaction, and in an instant all three leaped toward the pantry. Each took what was nearest at hand, and in a very few moments there was a reasonably large but varied collection of canned provisions in the yawl. No water had been put on board for the very good reason that they could not find a breaker; and Jim shouted, after they had searched several moments in vain:
"We shall have to leave without anything to drink, for we can't get one of the scuttle-butts on the boat."
"I'll stand a pretty good scorchin' afore startin' like that," Bob said decidedly, "'cause you see I know what it is to be thirsty. Fill half a dozen of the fire-buckets while I hunt after bottles."
During all this time the smoke had been pouring from the fore hatchway in dense clouds, apparently giving evidence of some mighty conflagration below; but before a supply of water could be put on the yawl it had fined down to a thin curl of vapor, and to this Jim called Bob's attention just as they were preparing to lower the boat.
"It looks as if somethin' had put the fire out," he said; and Bob replied, as he let go the davit-falls:
"Make fast there, lads, an' I'll take a look below. We don't want to abandon the brig while there's a chance of standin' by her."
The old sailor went forward, the boys remaining aft ready to lower away at a moment's notice, and in a few seconds, to the surprise of all, he was seen going below.
"Now, that's what I call queer!" Jim said after five minutes had passed and Bob did not make his appearance. "He couldn't stay down there very long if the fire amounted to much."
"Perhaps he's been suffocated and can't get back," Harry suggested in a low, tremulous tone.
This idea was sufficient to alarm the other boys, and stopping only long enough to make the falls fast they rushed forward, reaching the fore hatchway just as Bob began to ascend.
"Is the fire very big?" Jim asked; and the reply astonished them quite as much as had the explosion.
"There ain't even a spark!"
"Then what caused the smoke?"
