wiftly across the
great continent. By noon he sighted Chicago, and after a brief
inspection of the place from the air determined to devote at least an
hour to forming the acquaintance of this most wonderful and
cosmopolitan city.

18. A Narrow Escape

The Auditorium Tower, where "the weather man" sits to flash his reports
throughout the country, offered an inviting place for the boy to
alight. He dropped quietly upon the roof of the great building and
walked down the staircase until he reached the elevators, by means of
which he descended to the ground floor without exciting special
attention.

The eager rush and hurry of the people crowding the sidewalks impressed
Rob with the idea that they were all behind time and were trying hard
to catch up. He found it impossible to walk along comfortably without
being elbowed and pushed from side to side; so a half hour's
sight-seeing under such difficulties tired him greatly. It was a
beautiful afternoon, and finding himself upon the Lake Front, Rob
hunted up a vacant bench and sat down to rest.

Presently an elderly gentleman with a reserved and dignified appearance
and dressed in black took a seat next to the boy and drew a magazine
from his pocket. Rob saw that he opened it to an article on "The
Progress of Modern Science," in which he seemed greatly interested.

After a time the boy remembered that he was hungry, not having eaten a
tablet in more than twenty-four hours. So he took out the silver box
and ate one of the small, round disks it contained.

"What are those?" inquired the old gentleman in a soft voice. "You are
too young to be taking patent medicines."

"There are not medicines, exactly," answered the boy, with a smile.
"They are Concentrated Food Tablets, sorted with nourishment by means
of electricity. One of them furnishes a person with food for an entire
day."

The old gentleman stared at Rob a moment and then laid down his
magazine and took the box in his hands, examining the tablets curiously.

"Are these patented?" he asked.

"No," said Rob; "they are unknown to any one but myself."

"I will give you a half million dollars for the recipe to make them,"
said the gentleman.

"I fear I must refuse your offer," returned Rob, with a laugh.

"I'll make it a million," said the gentleman, coolly.

Rob shook his head.

"Money can't buy the recipe," he said; "for I don't know it myself."

"Couldn't the tablets be chemically analyz