"So do those on the other boats, if the observable excitement is to be taken as an indication," laughed Mr. Farnum.
"This letter goes on to request," announced Benson, "that the commander of each submarine willing to enter this affair signal to the 'Oakland' by hoisting the signal 'Ready.' Do you hear that, Eph?"
Somers made a dash for the signal chest. In another moment the appropriate bit of bunting was fluttering on the halliard at the top of the signal mast.
"We are directed," Jack read on, "to be ready within thirty minutes. We must follow the 'Oakland' down the bay at a cruising speed of sixteen miles an hour. Once out of the bay, the 'Oakland' will signal our formation to us."
"Do you see the boat the Rhinds signal is going up on?" laughed Hal Hastings. "It is going up on the submarine 'Thor.' According to the old Norsemen tales Thor was The Thunderer—also the fellow who struck with the big hammer. It looks like a Rhinds boast that they are to do big things on this lightning cruise."
"Yes; Thor was an old Norse god," muttered Captain Jack. "And the early Norsemen were very largely pirates. Perhaps we are to take the signal on the 'Thor' as an intimation that Rhinds is out to play pirate in earnest on this cruise."
As Benson uttered these words he felt an odd little shiver run over him. Yet he gave it no more thought. Little idea had he, at that moment, how prophetic his words were likely to be!
In half an hour, as planned, the "Oakland," after firing a warning gun, steamed away from her moorings. Gradually the gunboat's speed increased, until the full sixteen miles were being made—miles, instead of knots, since gasoline boats, like these submarines, are usually rated by miles instead of by the longer "knot."
It was a rattling rate of speed to exact from these little craft, when it was considered that the gait would have to be continued, without break, for at least twenty-four hours.
Eph was at the wheel, at the start, and Jack standing back by the conning tower. Mr. Farnum had gone below, for a nap, as he intended to relieve Hal in the engine room after a few hours.