"Hear! Hold on! Quit shovin' me!" cried Washington White. "Stop, Massa Jack!"
"I'm not pushing you," replied the boy, who, with the others, was being moved forward against his will. "I can't seem to stop!"
Nor could the rest of them. It was just as if some one had commanded them to walk forward toward the crowd that stood waiting for them, and they could no more avoid obeying than they could had they been pulled by wire cables.
"What can it be?" murmured Mr. Roumann. "Hold back, all of you. They must have attached invisible wires to us, and are going to make prisoners of us!"
"There are no wires on me," observed Mark, carefully feeling about him.
"Nor me, either," added Jack.
"I'll soon make 'em stop!" exclaimed Andy Sudds, and raising his gun to his shoulder, he fired over the heads of the Martians, intending to frighten them.
To the surprise of the adventurers the gun only made a faint sound, about half as loud as it usually did, and they saw something small and black pop out of the muzzle, and sail lazily through the air for a short distance, then fall.
"Would you look at that!" exclaimed the hunter in great disgust. "Look how my bullet flew! First time I ever saw a bullet come from a gun! We're in a strange land, friends!"
"I have it!" cried Professor Henderson. "The attraction of gravitation on Mars is a third of that on the earth. The atmosphere is also less dense. Your gun only makes half the noise, Andy, and the bullet doesn't go nearly as fast, nor with nearly so much force. That's why you could see the bullet. It went very slowly. Your gun is of no use here."