Tom had many adventures on his motor-cycle, and, later on he secured a motor-boat, in which he beat his enemy, Andy Foger, in a race.  Next Tom built an airship, and in this he went on a wonderful trip.  Returning from this he and his 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 tells of a new machine he invented—­an air-glider—­ which he used to save the exiles of Siberia, incidentally, on that trip, finding a valuable deposit of platinum.

As I have said, it was on his trip to giant land that Tom got his big servant.  This book, the thirteenth of the series, is called “Tom Swift in Captivity,” for the giants captured him and his friends, and it was only by means of their airship that they made their daring escape.

Tom had been back from the strange land some time now.  One giant he had turned over to the circus representative for whom he had undertaken the mission, and the other he retained to work around his shop, as Eradicate was getting too old.  It was now winter, and there had been quite a fall of snow the day before Mr. Period, the odd moving picture man, called on Tom.  There were many big drifts outside the building.

Tom had fitted up a well-equipped shop, where he and his father worked on their inventions.  Occasionally Ned Newton, or Mr. Damon, would come over to help them, but of late Tom had been so busy on his noiseless motor that he had not had time to even see his friends.

“Well, I guess the five minutes have passed, and my mind is made up,” thought Tom, as he looked at his watch.  “I might as well tell Mr. Period that I can’t undertake his commission.  In the first place it isn’t going to be an easy matter to make an electric moving picture camera.  I’d have to spend a lot of time studying up the subject, and then I might not be able to get it to work right.