“If an aircraft flies or attempts to fly over any area prescribed under this Act for the purposes of the defence or safety of the realm ... it shall be lawful for any officer designated for the purpose by regulations made by the Secretary of State, to cause such signal as may be prescribed by those regulations to be given, and, if after such signal has been given the aircraft fails to respond to the signal ... it shall be lawful for the officer to fire at or into such aircraft, and to use any and every other means necessary to compel compliance.” Guns for use against aircraft have already been placed around our coasts, and some of these would be employed no doubt to fire upon a pilot who seemed deliberately to break the law; but this assumes of course that he is visible; were he flying very high, or were clouds to obscure the view, he might defy the officials who watched below. Just what may happen, when such laws are required for daily use, time alone will show; at present, beyond the bringing to our police courts of certain foreign pilots who have flown above prohibited areas on their way from France to Hendon, no data is available; and these offending airmen, pleading that they had no knowledge of the new laws, have been treated leniently by magistrates. The whole question of aerial law must be considered seriously by the nations; and in view of the preparation of some general code of rules the International Aeronautical Federation--which is the central authority upon aviation, and represents the world’s Aero Clubs--has held many meetings and drafted a number of proposals. It is held, to begin with, that all aircraft must be registered, and that an international list of machines must be compiled; also that craft must be marked with letters indicating their nationality--such as “G.B.” for Great Britain and “F” for France. By such means, and particularly by use of an international register, any craft could be identified, even if flying in a foreign country; and should it escape observation while in the air by flying high, it would need ultimately to land, and would then have its identity revealed. The pilot in charge would have identification papers, and a certificate showing his proficiency. The rules for obtaining such a certificate, in days when men take charge of large passenger machines, will need to be more exacting than they are at the present time; and it is argued that, before he is put in control of such a craft, an airman should pass a medical examination so as to show he is organically sound, and fit both in eyesight and nerve to steer a high-speed, powerful machine.