ion of New York City against an air raid by a
hostile foreign power. At the moment, of course, there was no
danger. The only hostile foreign power with any considerable naval
or aerial force was Germany and her fleet was securely bottled up in
her own harbours by the overpowering fleet of Great Britain. Yet if
one could imagine the British fleet reduced to inefficiency, let us
say by a futile, suicidal attack upon Kiel or Heligoland which would
leave it crippled, and free the Germans, or if we could conceive
that the German threat to reduce Great Britain to subjection by the
submarine campaign, proved effective, the peril of New York would
then be very real and very immediate. For, although the harbour
defences are declared by military authorities to be practically
impregnable against attack by sea, they would not be effective
against an attack from the air. A hostile fleet carrying a number of
seaplanes could round-to out of range of our shore batteries and
loose their flyers who could within less than an hour be dropping
bombs on the most congested section of Manhattan Island. It is true
that our own navy would have to be evaded in such case, but the
attack might be made from points more distant from New York and at
which no scouts would ever dream of looking for an enemy.

The development in later months of the big heavily armed cruising
machines makes the menace to any seaport city like New York still
greater. The Germans have built great biplanes with two fuselages,
or bodies, armoured, carrying two machine guns and one automatic
rifle to each body. They have twin engines of three hundred and
forty horse power and carry a crew of six men. They are able in an
emergency to keep the air for not less than three days. It is
obvious that a small fleet of such machines launched from the deck
of a hostile squadron, let us say in the neighbourhood of Block
Island, could menace equally Boston or New York, or by flying up the
Sound could work ruin and desolation upon all the defenceless cities
bordering that body of water.

Nor are the Germans alone in possessing machines of this type. The
giant Sikorsky machines of Russia, mentioned in an earlier chapter,
have during the war been developed into types capable of carrying
crews of twenty-five men with guns and ammunition. The French, after
having brought down one of the big German machines with the double
bodies, instantly began building aircraft of their own of an even
sup