“Stop it!  You’ll make me blush!” cried the Black Hawk’s owner as he tried the different gages and levers to see that they were all right.

After what seemed like a long time he gave the word for those who were to make the trial trip to take their places.  They did so, and then, with Mr. Jackson, Tom went to the engine room.  There was a little delay, due to the fact that some adjustment was necessary on the main motor.  But at last it was fixed.

“Are you all ready?” called Tom.

“All ready,” answered Mr. Damon.  The old elephant hunter sat in a chair, nervously gripping the arms, and with a grim look on his tanned face.  Mr. Swift was cool, as Ned, for they had made many trips in the air.  Outside were Eradicate Sampson and Mrs. Baggert.

“Here we go!” suddenly cried Tom, and he yanked over the lever that started the main motor and propellers.  The Black Hawk trembled throughout her entire length.  She shivered and shook.  Faster and faster whirled the great wooden screws.  The motor hummed and throbbed.

Slowly the Black Hawk moved across the ground.  Then she gathered speed.  Now she was fairly rushing over the level space.  Tom Swift tilted the elevation rudder, and with a suddenness that was startling, at least to the old elephant hunter, the new airship shot upward on a steep, slant.

“The Black Hawk flies!” yelled Ned Newton.  “Now for elephant land and the big tusks!”

“Yes, and perhaps for the red pygmies, too,” added Tom in a low voice.  Then he gave his whole attention to the management of his new machine, which was rapidly mounting upward, with a speed rivalling that of his former big craft.

CHAPTER VIII

OFF FOR AFRICA

Higher and higher went the Black Hawk, far above the earth, until the old elephant hunter, looking down, said in a voice which he tried to make calm and collected, but which trembled in spite of himself: 

“Of course I’m not an expert at this game, Tom Swift, but it looks to me as if we’d never get down.  Don’t you think we’re high enough?”

“For the time being, yes,” answered the young inventor.  “I didn’t think she’d climb so far without the use of the gas.  She’s doing well.”

“Bless my topknot, yes!” exclaimed Mr. Damon.  “She beats the Red Cloud, Tom.  Try her on a straight-away course.”

Which the youth did, pointing the nose of the craft along parallel to the surface of the earth, and nearly a mile above it.  Then, increasing the speed of the motor, and with the big propellers humming, they made fast time.

The old elephant hunter grew more calm as he saw that the airship did not show any inclination to fall, and he noted that Tom and the others not only knew how to manage it, but took their fight as much a matter of course as if they were in an automobile skimming along on the surface of the ground.