one else's property, where
one not only could dig for arrow-heads, but find them. The professor was
delighted, but for Jimmie it was a great disappointment. The week
following Jimmie was again disappointed.

On the bank of the Kensico Reservoir, he came upon a man who was acting
in a mysterious and suspicious manner. He was making notes in a book,
and his runabout which he had concealed in a wood road was stuffed with
blue-prints. It did not take Jimmie long to guess his purpose. He was
planning to blow up the Kensico dam, and cut off the water supply of New
York City. Seven millions of people without water! Without firing a
shot, New York must surrender! At the thought Jimmie shuddered, and at
the risk of his life, by clinging to the tail of a motor truck, he
followed the runabout into White Plains. But there it developed the
mysterious stranger, so far from wishing to destroy the Kensico dam, was
the State Engineer who had built it, and, also, a large part of the
Panama Canal. Nor in his third effort was Jimmie more successful. From
the heights of Pound Ridge he discovered on a hilltop below him a man
working along upon a basin of concrete. The man was a German-American,
and already on Jimmie's list of "suspects." That for the use of the
German artillery he was preparing a concrete bed for a siege gun was
only too evident. But closer investigation proved that the concrete was
only two inches thick. And the hyphenated one explained that the basin
was built over a spring, in the waters of which he planned to erect a
fountain and raise goldfish. It was a bitter blow. Jimmie became
discouraged. Meeting Judge Van Vorst one day in the road he told him his
troubles. The young judge proved unsympathetic. "My advice to you,
Jimmie," he said, "is to go slow. Accusing everybody of espionage is a
very serious matter. If you call a man a spy, it's sometimes hard for
him to disprove it; and the name sticks. So, go slow--very slow. Before
you arrest any more people, come to me first for a warrant."

So, the next time Jimmie proceeded with caution.

Besides being a farmer in a small way, Jimmie's father was a handy man
with tools. He had no union card, but, in laying shingles along a blue
chalk line, few were as expert. It was August, there was no school, and
Jimmie was carrying a dinner-pail to where his father was at work on a
new barn. He made a cross-cut through the woods, and came upon the young
man in the golf-cap. The stran