In this connection the two voyages across the Atlantic of the British government airship R-34, not long after Alcock and I had returned to London, was a big step towards the age of regular air service between Britain and America. With five motors the _R-34_ could carry on if one, or even two of them were out of action. In fact, on its return flight, one motor broke down beyond the possibility of immediate repair; although there were ample facilities and an ample crew for effecting immediate repairs in the air. Yet she completed her journey without difficulty. With a disposable lift of twenty-nine tons, the airship carried plenty of fuel for all contingencies, an adequate crew, and heavy wireless apparatus that could not have been fitted on the larger aëroplanes. Despite all this preliminary weight, a large collection of parcels, letters and newspapers were taken from America to England in record time. Had the weather conditions been at all suitable she could easily have brought the mail direct from New York to London by air. All honor to General Maitland, Major Scott and the other men who carried out this astonishing demonstration so early as July, 1919. Even vessels of the _R-34_ type, however, are quite unsuitable for regular traffic across the Atlantic. Much bigger craft will be needed if the available space and the disposable lift are to be sufficient for the carrying of freight or passengers on a commercial basis. Already the construction of airships two and a half and five times the size of the _R-34_, with approximate disposable lifts of one hundred and two hundred tons respectively, is projected. When such craft are accomplished facts, and when further progress has been made in solving weather and navigation problems, we may look for transatlantic flights on a commercial basis. CHAPTER IX THE NAVIGATION OF AIRCRAFT I do not claim to be an especial authority on the theory of navigation--indeed, it was as a prisoner of war that I first took up seriously the study of that science. But I believe that sustained and sufficient concentration can give a man what he wants; and on this assumption I decided to learn whatever might be learned about navigation as applied to aircraft. As yet, like most aspects of aëronautics, this is rather indefinite, although research and specially adapted instruments will probably make it as exact as marine navigation. Navigation is the means whereby the mariner or aviator ascertains his position on the surface of the earth, and determines the exact direction in which he must head his craft in order to reach its destination. The methods of navigation employed by mariners are the result of centuries of research and invention, but have not yet reached finality--witness the introduction within the last few years of the Gyroscopic Compass and the Directional Wireless Telegraph Apparatus, as well as of improved methods of calculation.