ten o'clock
So he sat at his table , tuning now to this wave length and now to that , now catching a land message and now one from the sea . Distinctly he caught the signal NAA from the great navy wireless plant at Arlington . He recognized it before the operator had finished sending his call signal . Night after night with his home-made outfit at Central City , Henry had heard this station send forth the time signals at ten o'clock ; and during his brief period as radio man for Uncle Sam he had often talked with Arlington , both sending and receiving messages from the great station . But though he recognized the voice , he did not know the language he heard ; for Arlington was flinging abroad a message in the secret code of the navy . Press messages and commercial communications were buzzing through the air like swarms of bees . Orders to departing steamships came surging over his line .