THE future of the rigid airship from the commercial point of view is brought prominently into notice by a paper lately issued by the Air Ministry entitled “Notes on Airships for Commercial Purposes.” This memorandum discusses at length the possibility of the use of airships in the immediate future, and enters into a detailed1 comparison between the large aeroplane and the rigid airship. At the outset it is stated, however, that the two types of aircraft, as at present developed, are not likely to compete with one another seriously, since their characteristics are widely different, the aeroplane being essentially a highspeed, short-distance machine, while the rigid airship is a long-distance, weight-carrying craft. The great endurance of the airship and its power of remaining in the air during a temporary breakdown of the machinery are valuable assets when long flights over sea or mountainous country are contemplated. The safety and comfort of passengers are considered to be greater in the case of the airship than in that of the aeroplane. In connection with the possibility of loss by fire in the former case the Air Ministry -points.out that there has: been only one such loss since 1914, despite the fact that about 2½ million miles have been covered, and that in this one case the cause of fire has been ascertained and eliminated. It is conceded that at present the airship is more affected by bad weather than the aeroplane, but it is stated that up to the end of November there were only nine days in 1918 on which no airship flight took place in the British Isles.