Rubber

Its rubber seals and movable parts make it watertight, and it uses specialized lights to navigate in deep waters.

Here, too, were vast plantations, and east of the mountains were regularly planted groves of the rubber tree, the genuine Siphonia Elastica of botany.

Like all vailx of the class to which it belonged, ours was constructed for both aerial and submarine service, the plates of the sliding deck and the other movable parts of the hull being capable of very close approximation by means of set screws and rubber washers.