Viewing page 22 of 37

This transcription has been completed. Contact us with corrections.

the equilibrator as might be necessary could at any time be permitted to drag upon the surface of the earth.  It might happen, at any time, that during an interval of bright sunshine the gas absorbed radiant heat and reached a temperature 20 degrees higher than that of the surrounding air, and that the rapid cooling of the gas, due to clouds or snowstorm, might involve a rapid loss of 30 degrees or 1,200 pounds of buoyancy.  But in such case, instead of wasting ballast, the equilibrator is ready to be used in full compensation.

In another important particular the physical characteristics of the polar ocean favor the making of a long voyage by airship.  It is impossible, in the present state of the art, to build gas airships with enough speed and endurance to enable them surely to defeat

[[image]]
Hydrogen Gas Apparatus -- Built in Paris and Erected in Spitzbergen.

any adverse wind which they may encounter, as does the steamship of the sea.  For this reason -- unless great advance can be made, not now within sight -- the gas buoyed aerial craft must always be considered as giving us aerial navigation with limitations.  These

17