A feature in the situation which impressed both Congress and the American people was the exposure by various military experts of the defenceless condition 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 a๋rial 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 superior type. Some of these are driven by four motors and carry eleven persons, besides guns and ammunition. The Caproni machines of Italy are even bigger--capable of carrying nine guns and thirty-five men. The Congressional Committee was much impressed by consideration of what might be done by a small fleet of aircraft of this type launched from a hostile squadron off the Capes of Chesapeake Bay and operating against Washington. It is not likely that any foreign foe advancing by land could repeat the exploit of the British who burned the capitol in 1812. But in our present defenceless state a dozen aircraft of the largest type might reduce the national capitol to ruins.
If an enemy well provided with a๋rial force possesses such power of offence an equal power of defence is given to the nation at all well provided with flying craft. In imitation, or perhaps rather in modification, of the English plan for guarding the coasts of Great Britain, a well matured system of defending the American coasts has been worked out and submitted to the national authorities. It involves the division of the coasts of the United States into thirteen aeronautical districts, each with aeronautical stations established at suitable points and all in communication with each other. Eight of these districts would be laid out on the Atlantic Coast extending from the northern boundary of Maine to the Rio Grande River.
Just what the purpose and value of these districts would be may be explained by taking the case, not of a typical one, but of the most important one of all, the third district including the coast line from New London, Conn., to Barnegat Inlet, New Jersey. This of course includes New York and adjacent commercial centres and the entrance to Long Island Sound with its long line of thriving cities and the ports of the places from which come our chief supplies of munitions of war. It includes the part of the United States which an enemy would most covet. The part which at once would furnish the richest plunder, and possession of which by a foe would most cripple this nation. To-day it is defended by stationary guns in land fortresses and in time of attack would be further guarded by a fringe of cruising naval vessels. Apparently up to the middle of 1917 the government thought no a๋rial watch was needed.