HERE are few forms of transport which are not influenced to some extent by meteorological conditions, but there is none which makes greater demands on meteorological science and practice than the aeroplane and the airship. The importance which is attached by the Air Ministry to the provision of the necessary meteorological advice and organisation in connexion with the development of Empire air routes is rendered evident by a document recently issued under the title of "The Approach towards a System of Imperial Air Communications "(H.M. Stationery Office, price 5s.). This document consists of the memorandum by the Secretary of State for Air laid before the Imperial Conference, 1926, together with the report of the Imperial Air Communications Special Sub-Committee. The memorandum contains appendices giving a clear statement of the principles governing the application of meteorology to air navigation, both as regards investigational work and as regards the provision of a ground organisation along the routes. At the same time, the main portion of the memorandum sets out, in the section on airships, some general remarks on the bearing of meteorological conditions on airship navigation, supported by very interesting examples of the results to date of an intensive meteorological investigation of the projected England-Egypt-India airship routes, illustrated by charts well reproduced in colours. Meteorological work for airships is in the hands of a specially created division of the Meteorological Office, and it is hinted that the aim of the work on the England-India routes is to provide for the airship pilot, information in atlas and handbook form analogous to that which has long been available to seamen.