6. Recognition of the right of crossing one country to another, with the privilege of landing, but under the reservation of the right of the state crossed to apply its local rules, and if necessary to force the landing of the visiting machines on signal. 7. Recognition of the principle of mutual indemnity to cover damages to persons or property due to aircraft--the state of the offending machine to make reparation and then to recoup itself in any way it sees fit. 8. Recognition of the necessity of a permanent international aëronautical commission, in order to keep the development of the legal side of aviation abreast of the development of the science itself. 9. Recognition of the obligation of each state to regulate its internal legislation along the lines of the clauses of the international agreement. The main airways of the world are still hypothetical, but some of their main terminals, in relation to the centers of industry and population and the trade routes, will certainly be London, New York, San Francisco, Tokio, Delhi, Colombo, Cairo, Cape Town, and Rio de Janeiro. In particular London, New York, Cairo and Rio de Janeiro are fitted to be great junctions for air traffic. London is the logical distribution center for passengers and freight from North and South America bound for Continental Europe or the East. The New York terminal should link the transatlantic airways from Europe with the airways of North America. Rio de Janeiro should perform the same function for South America, and also be the center of seaplane traffic up the Amazon. Cairo is destined to be the junction for the air routes between Europe, Asia, Africa and Australia. From it dirigibles or aëroplanes may pass to India (via Damascus and Bagdad), to Cape Town (via Nairobi), to Australia (via Aden and Colombo, or Delhi and Singapore), and to London (via Algiers or some point in Southern Italy). Cairo is also likely to be an important base for seaplanes and flying boats plying up and down the tremendous waterways of the Nile and the Great Lakes. The British Empire is especially bound up with the airways of the future. The geographical position of the Briton forces him to think in Imperial terms. In 1776 Great Britain lost her most valuable colonies largely because the Atlantic Ocean made adequate representation of the colonial interest physically impossible. Since that day cables, steamships and the wireless have helped to overcome the distances that separate the overseas dominions from the British Isles. Aircraft and well-organized British air routes should be the greatest step in the consolidation of the far-flung Empire.