father heard about a treasure sunken under the ocean. In his submarine boat Tom secured the valuables, and made a large sum for himself.
In his electric runabout, which was the swiftest car on the road, Tom was able to save from ruin a bank in which his father was interested, and, a short time after that, he went on a trip in an airship, with a man who had invented a new kind. The airship was smashed, and fell to Earthquake Island, where there were some refugees from a shipwreck, among them being the parents of Mary Nestor. In the volume called "Tom Swift and His Wireless Message," I told how he saved these people.
When Tom went among the diamond makers he had more strange adventures, on that trip discovering the secret of phantom mountain. He had bad luck when he went to the caves of ice, for there his airship was wrecked.
When Tom made the trip in his sky racer he broke all records for an aerial flight, incidentally saving his father's life. It was some time after this when he invented an electric rifle, and went to elephant land, to rescue some missionaries from the red pygmies.
The eleventh volume of the series is called "Tom Swift in the Land of Gold," and relates his adventures underground, while the next one
