That afternoon found the Holland lying off shore about two miles from the city.
It was rumored that seven other foreign ships were coming, but so far they were still out of sight.
Suddenly a strange rumble rent the air, coming from the depths of the sea.
The terrific explosion of the morning had loosened some rocks of the reefs outside of the harbor and now followed a regular under-water earthquake.
The disturbance was a violent one, and brought on a tidal wave which arose to a height of fifteen feet.
"Hi, look!" screamed Andy to Oscar.
Both were on the deck of the Holland at the time, and before they could go below the craft was caught by the tidal wave and carried rapidly toward shore.
Over the beach swept the wave, carrying the Holland with it, a distance of two hundred feet and more.
Then the wave went down almost as suddenly as it had arisen, and the young captain found his submarine craft high and dry on the rocks, three hundred feet from water deep enough to float her!
There was great confusion on board, and in the midst of this came another alarm.