Great Britain had almost a monopoly of maritime commerce in the Gulf, and was alone responsible for buoying, lighting and policing its waters.
Another and very obvious difficulty is traceable to the great disparity in the weight of air as compared with any known solid, and the consequent want of buoying or sustaining power which that disparity involves.
The amount of canvas or oiled silk necessary for buoying up the machine is stated to be equal to one square foot for each half pound of weight."