We began at the very beginning on an elaborate system.
The first thing was to adequately fortify the Blue Mouth.

Whilst the fortifications were being constructed we kept all the warships in the gulf.

But when the point of safety was reached, we made the ships do sentry-go along the coast, whilst we trained men for service at sea.

It is our plan to take by degrees all the young men and teach them this wise, so that at the end the whole population shall be trained for sea as well as for land.

And as we are teaching them the airship service, too, they will be at home in all the elements--except fire, of course, though if that should become a necessity, we shall tackle it too! We started the Great Tunnel at the farthest inland point of the Blue Mouth, and ran it due east at an angle of 45 degrees, so that, when complete, it would go right through the first line of hills, coming out on the plateau Plazac.