When we consider the rapid development of the rigid airship since
1914, it should not be insuperable to construct an airship with
the capabilities suggested by General Sykes. In 1914, the
average endurance of the Zeppelin at cruising speed was under one
day and the maximum full speed about 50 miles per hour. In 1918,
the German L 70, which is of 2,195,000 cubic feet capacity, the
endurance at 45 miles per hour has risen to 7.4 days and the
maximum full speed to 77 miles per hour. The "ceiling" has
correspondingly increased from 6,000 feet to 23,000 feet.

The British R 38 class, at present building, with a capacity of
approximately 2 3/4 million cubic feet has an estimated endurance
at 45 miles per hour of 211 hours or 8.8 days, which is 34 hours
greater than the German L 70 class. It is evident that for a
ship of this calibre the crossing of the Atlantic will possess no
difficulty, and as an instance of what has already been
accomplished in the way of a long-distance flight the exploit of
a Zeppelin airship based in Bulgaria during the war is
sufficiently remarkable. This airship in the autumn of 1917 left
the station at Jamboli to carry twelve tons of ammunition for the
relief of a force operating in German East Africa. Having
crossed the Mediterranean, she proceeded up the course of the
Nile until she had reached the upper waters of this river.
Information was then received by wireless of the surrender of the
force, and that its commander, Von Lettow, was a fugitive in the
bush. She thereupon set out for home and reached her station in
safety, having been in the air 96 hours, or four days, without
landing.