on
and I happened to be near by and brought you here. Fortunately I am
something of a doctor as well as an inventor, and I used a strong
medicine I have."

"I'm sure we're much obliged to you," answered Mark.

"Let me see how much improved you are by eating," suggested the old man.
"I can trust Washington to cook good meals, even if he does use big
words."

Then, while the colored man grinned cheerfully at them, Jack and Mark,
sitting up on the bed, for they were still weak and sore, ate the broth.
After that both boys said they felt better.

"See if you can walk," suggested the inventor.

Mark and Jack stepped on the floor. They both uttered cries of pain.
They were stiff and lame from the shaking they had received.

"A day in bed will do you no harm," said their strange rescuer. "I have
some liniment that will soon take the soreness out of every one of your
muscles."

Though the boys protested at being made to remain in bed, the old man
insisted. He made them take off most of their clothes, and then brought
out some liniment. Under his direction Jack and Mark rubbed themselves
well, and experienced almost immediate relief. It was now getting dusk,
and Washington lighted a big lamp that hung in the centre of the room,
first taking care that the shutters were tightly fastened.

The colored man prepared a simple supper for Mr. Henderson, and
afterward got himself a meal. When the dishes were cleared away the old
man, who had noted with smiles the anxious glances Jack and Mark were
casting about the strange room, said:

"I suppose you boys would like to ask lots of questions."

"I'd like to know what all this machinery is for," spoke Jack.

"And what is behind that door," Mark went on, indicating the much-locked
portal.

"I knew it!" exclaimed the old man. "I knew it! Now if I tell you will
you promise to keep it a secret until I give you leave to speak?"

Of course the boys promised eagerly.

"Do you think you have rested enough now to take a look inside?" the
inventor asked, nodding toward the locked door.

"Sure!" exclaimed Jack.

"Then put on your coats and trousers and I'll introduce you to my pet."

Wonderingly, the boys followed him. It took nearly a minute to unfasten
the various bolts and bars, but at last the portal swung open. The place
was dimly lighted by a single big lamp, but in the glare of it the boys
caught sight of a strange, weird object. It looked like an immense
cigar, and swaye