"Bless my spark-plug!" gasped Mr. Wakefield Damon.

Either from nervousness or intention, he jerked the steering
wheel so that the car made a sudden leap away from the curb. The
figure of the stranger swayed.

Instantly Tom Swift struck the man's arm up higher and from
under his own coat appeared something that bulked like a pistol
in his right hand. He had intimated to Mary Nestor that he
carried something with which to defend himself from highwaymen if
he chose to. This invention, his ammonia gun, now came into play.

"Bless my failing eyesight!" exclaimed Mr. Damon, as he shot
the motor-car ahead again in a straight line.

The man who had accosted Tom so fiercely fell off the running
board and rolled into the gutter, screaming and choking from the
fumes from Tom's gun.

"Drive on!" commanded the young inventor. "If he keeps
bellowing like that the police will pick him up. I guess he will
let us alone here-after."

"Bless my short hairs and long ones!" chuckled Mr. Damon. "You
are the coolest young fellow, Tom, that I ever saw. That man must
have been a highwayman. And it is of some of those gentry that I
drove over to Shopton this evening to talk to you about."