“A magnificent specimen.  One of the finest I have ever seen.  Most remarkable!”

And with that he popped the bit of stone into his bag, which the boys now saw was filled with similar objects.

“Maybe he’ll let us get by now,” remarked Tom, but a sudden exclamation from Dick Donovan cut him short.

“Why, hullo, professor,” he said, “out collecting specimens?”

The little man peered at him sharply.  And then broke into a smile of recognition.

“Why, it’s Dick Donovan!” he beamed, hastening up to the car, “the young journalist who wrote an article about my specimens once and woefully mixed them up.  However, to an unscientific mind——­”

“They are all just rocks,” finished Dick with a grin.

“I have had unusual success to-day,” said the professor, who appeared not to have heard the remark.  “I must have at least fifty pounds of specimens on my back at this minute.”

He broke off suddenly.  The next moment he darted off to the side of the road and chipped off a fragment of rock from a bank that overhung it.

“This is lucky, indeed,” he exclaimed, holding it up to the light so that some specks in the gray stone sparkled.  “An extremely rare specimen of mica that I had no idea existed in this part of New England.”

The odd little man opened his bag and introduced his latest acquisition into it While he was doing this Dick had been explaining to the boys: 

“He’s a queer character.  Professor Jerushah Jenks.  They say he’s a great authority on mineralogy and so on.  I interviewed him once.  He’s always out collecting.”

“Does he always carry a quarry like that around on his back?” asked Tom.

“Always when he’s getting specimens,” Dick whispered back.

By this time the professor, his eyes agleam over his latest discovery, was back at the side of the car.

“Ah, my beauty, I have you safe now,” he said, patting the side of the bagful of specimens.  “Boys, this is my lucky day.”

The boys could hardly keep from smiling at the little man’s delight.  It appeared hard to believe that anyone could find pleasure in packing about a sackful of heavy rocks on a hot day.  But the professor’s eyes were sparkling.  It was clear he considered himself one of the most fortunate of men.

Dick introduced the boys and, to their surprise, the professor declared that he had read of their various adventures and inventions.

“We are actually fellow adventurers in the field of science,” he cried, rattling his bag of specimens enthusiastically.  “Some time I should like to call on you and see your workshops.”

“You will be welcome at any time,” said Jack cordially, and then the professor declared that he must be getting home.

“If we are going your way we can give you a ride,” said Tom.

“Thank you, I’ll accept that invitation.  But what an odd-looking automobile you have there.”