beginning their study of
the city. When Captain Hardy emerged from the wireless room, he ran his
eye over the contents of the bookshelves; and one section he discovered
was filled with maps and guide-books and local histories, not only of New
York but also of other American cities. He found a large-scale map of
the metropolis and spread it out on the table, true to the indicated
compass points. Clustered about this outspread map, the other members of
the patrol followed with eager eyes and retentive minds their
instructor's every word.

Dr. Hardy called their attention to the contour of Manhattan Island, long
and tongue-shaped, and running almost north and south. He showed them
the main thoroughfares, the great arteries of north and south traffic.
He traced for them the routes of subway, surface, and elevated car lines.
Together they located the tunnels and the ferries. They studied the
harbor and the different shipping districts, coming quickly to know where
the transatlantic liners docked, where the coastwise steamers were
berthed, and where tramp steamers could find safe anchorages. They
examined the harbor and adjacent waterways. They studied the locations
of police stations and hospitals, of passenger stations and freight
depots. They noted the location of the forts. They identified the sites
of the largest buildings.

When they had finished with Manhattan, they studied one by one the other
boroughs--the Bronx, the boroughs east of Manhattan, Staten Island, and
finally the Jersey shore, searching always for what would lend itself to
spying or the use of a secret wireless. Especially they studied all that
related to ships that cross the Atlantic.

Not in one evening or in one day was this accomplished, but through the
long hours of many days, as one boy after another took his turn at the
wireless. And between tricks at listening in or studying maps and
guide-books, they roamed the streets, traveled on subway and surface and
elevated trains, crossed the ferries, rode in the sightseeing motors,
visited the bridges, the museums, the public buildings, and within a
short time knew more about the topography and geography of the city than
nine-tenths of the people who lived in it. As they became accustomed to
the noise and the confusion and were able to find their way about with
ease, they scraped acquaintances on every side, and soon knew a multitude
of newsies, porters, policemen, truck drivers, car-conduc