The Institut then proceeded to deal with _bases_ relating to a time of war, but was unable to make much progress with them in the time available. The debate upon the "Régime juridique des aérostats" was not resumed at Christiania in 1911, nor is it likely to be at Oxford "in the autumn of the present year," as Mr. Cohen has been led to suppose. Other arrangements were found to be necessary, at a meeting which took place a week ago between myself and the other members of our _bureau_. I am, Sir, your obedient servant, T. E. HOLLAND. Oxford, May 30 (1913). ATTACK FROM THE AIR THE ENFORCEMENT OF INTERNATIONAL LAW Sir,--In his interesting and important address at the Royal United Service Institution, Colonel Jackson inquired: "Can any student of international law tell us definitely that such a thing as aerial attack on London is outside the rules; and, further, that there exists an authority by which the rules can be enforced?" As one of the students to whom the Colonel appeals I should be glad to be allowed to reply to the first of his questions. The "Geneva Convention" mentioned in the address has, of course, no bearing upon aerial dangers. The answer to the question is contained in the, now generally ratified, Hague Convention No. iv. of 1907. Art. 25 of the regulations annexed to this Convention runs as follows: "It is forbidden to attack or to bombard _by any means whatever (par quelque moyen que ce soit)_ towns, villages, habitations, or buildings which are not defended." It clearly appears from the "Actes de la Conférence," e.g. _T._ i., pp. 106, 109, that the words which I have italicised were inserted in the article, deliberately and after considerable discussion, in order to render illegal any attack from the air upon undefended localities; among which I conceive that London would unquestionably be included. I cannot venture to ask the hospitality of your columns for an adequate discussion of the gallant officer's second question, as to the binding force attributable to international law. Upon this I may, however, perhaps venture to refer him to some brief remarks, addressed to you a good many years ago, and now to be found at pp. 101 and 105 of the new edition of my "Letters to _The Times_ upon War and Neutrality (1881-1918)." I am, Sir, your obedient servant, T. E. HOLLAND. Oxford, April 24 (1914). ATTACK FROM THE AIR THE RULES OF INTERNATIONAL LAW