,000,000 60.7 643 79
3,000,000 91.1 736 90.4
4,000,000 121.4 810 99.5
5,000,000 151.8 872 107.2
6,000,000 182.2 927 113.9
7,000,000 212.5 976 119.9
8,000,000 242.8 1,021 125.5
9,000,000 273.3 1,061 130.4
10,000,000 303.6 1,100 135.1

In airships of their present capacity, in order to obtain the greatest
amount of lift possible, lightness of construction has been of
paramount importance. With this object in view duralumin has been
used, and complicated girders built up to obtain strength without
increase of weight. In a large ship with a considerable gain in lift,
steel will probably be employed with a simpler form of girder work. In
that way cheapness of construction will be effected together with
increased rapidity of output, and in addition the strength of the whole
structure should be increased.

The rigid airship of 10,000,000 cubic feet capacity will have a
disposable lift of over 200 tons available for fuel, crew, passengers,
and merchandise in such proportions as are desired. The endurance of
such a ship at a cruising speed of 45 miles per hour will be in the
neighbourhood of three weeks, with a maximum speed of 70 to 80 miles
per hour, and a "ceiling" of some 30,000 feet can be reached. This
will give a range of over 20,000 miles, or very nearly a complete
circuit of the globe.

For commercial purposes the possibilities of such a craft are enormous,
and the uses to which it could be put are manifestly of great
importance. Urgent mails and passengers could be transported from
England to America in under half the time at present taken by the
steamship routes, and any city in the world could be reached from
London in a fortnight.

In the event of war in the future, which may be waged with a nation
situated at a greater distance from this country than was Germany,
aircraft Of long endurance will be necessary both for scouting in
conjunction with our fleets and convoy duties. The British Empire is
widely scattered, and large tracts of ocean lie between the various
colonies, all of which will require protection for the safe-guarding of
our merchant shipping. The provision of a force of these large
airships will greatly add