against aircraft, projectiles infringing the Declaration of St. Petersburg, there would be any great wave of indignation created in the world at large. If, for example, we were to find our aircraft being knocked about by such means, we need not imagine that we should receive much compensation in the way of international sympathy. The author is not for a moment suggesting that we should initiate any departure from the accepted usage of warfare in this respect; he is rather questioning the ethics of a procedure by which a country, whose obligations and responsibilities are as wide and as heavy as those of Great Britain, and whose traditions and the force of public opinion make solemn contracts binding, should become a signatory to agreements which are always liable to be (and sometimes are) signed by the other party with his tongue in his cheek. At the best the signing of restrictive agreements relating to the conduct of war may at some time after turn out to be no more or less than the drawing of a cheque on another's banking account—a cheque that will be honoured in another man's blood.
§ 46. The One-Pounder as an Aeroplane Gun. For the time being we will take the restrictions imposed by international agreement as though they were restrictions imposed by Nature, and accept the fact that for the throwing of explosive or inflammable projectiles the "one-pounder" is the smallest gun available. At present this offers considerable difficulty in the case of an aeroplane. In order to throw a 14 oz, projectile with a muzzle velocity of 1,700 ft.-sec, the weight of gun and its mountings, including suitable recoil mechanism, could not be much less than 1 cwt., and with 100 rounds of ammunition the total would be about 2½ cwt. Now this weight alone cannot be considered in any sense prohibitive; in fact, it is no more than most of the existing machines in service would be able to carry. But the
72
