The Dominion. MONDAY, OCTOBER 19, 1908. THE LIMITS OF FLIGHT.

Dominion, Volume 2, Issue 331, 19 October 1908, Page 6

The Dominion. MONDAY, OCTOBER 19, 1908. THE LIMITS OF FLIGHT.

Although a large proportion of the almost daily cable messages relating to aerial navigation arc reports of accidents, the general idea in the public mind must bo that very great progress, of a real and practical kind, has been made in the conqucst of the air. This ia not the idea of Professor Newcomb, the eminent American astronomer and physicist, who discusses the possibilities of the future in the September Nineteenth Century. His views, which are certain to be widely discussed, are quite opposed to

"the widespread impression that aerial flight is soon to play an important part as an agency in commcrce." He admits the plausibility of tho argument that to deny a great future to aerial navigation is to, take up the position of those who onco ridiculed the idea that the steam engine would drive great ships around the world, and proceeds to enquire whether there is "any well-defined limit" to future improvement. Ho is not discussing tho practicability of flight—since that has been settled in tho affirmative—but whether there is any rational ground to hope that aerial flight will "servo some practical purpose in the world's work," whether the "airship" will "compete with the steamship, tho railway, or the mail-coach in the carriage of passengers or mails." He prefaces his enquiry with the warning that "no definite limit can be set to the possible future of knowledge, nor to results which may yet bo reached by its advance." There may some day bo a great physical revelation which will throw' on the scrap-heap all present forecasts as to future possibilities. It might be found for cxamplo that gravity might be controlled, or that an alloy ten times as rigid and tenacious as steel might be discovered. But" to-day's experimenters are accepting physical principles as they now stand, and' their prophecies are based on present' knowledge. Phofessou Newcomb then discussesthe two fundamentally different kinds of aerial vehicle—the aeroplane or "flying machine," and the dirigible balloon or "airship." The limits to tho development of tho flyer are very obvious: tho .drawbacks,, taken thiow. it A it^

Professor Newcomb's opinion, out of the field of competition. The flyer's carrying power depends, in any condition, upon the area of its planes, and to increase this power its superficial extent must bo increased. "A practically unmanageable area of supporting surface and a consequent weakening of the machine will be required for any important enlargement." Moreover, a flyer t supported only by its motion, cannot stop for repairs. It will fall, and, though the navigator may guide its fall, he cannot prevent it. This places it out of court as an agent in commerce, for, as Profesor Nkwcojib points out, "if a steamship were liable to go to the bottom the moment any accident occurred to her machinery, the twentieth century would have come upon us without steam navigation on the ocean." Neither of these drawbacks is incident to the airship—her buoyant power is proportional to her cubic contents, she can be enlarged in length, breadth and thickness; and as she will float at rest she can possibly stop for repairs. Tho question in this case is one of constructive engineeringHow large can we build her and yet keep her manageable i That she must bo very large in order to take part in commerce is easily demonstrated. Already ocean freights are very cheap, and they can be cheapened still further only by raising the index of "cargo per carrier" without ' equally raising the fuel index. Professor Newcojib calculates that "the Royal mail airship will have to consume several times as much coal as the engine of the Flying Scotchman if she is to carry the same burden," while "tho projector of an airship who would successfully compete with the steamship in ocean traffic must not permit his modesty to suggest beginning with dimensions less than a length of half a mile and a diameter of 600 feet." Picture this monster in a storm! On the credit side, of course, must be placed the fact that large areas of the earth's surface are not yet accessible by rail, but man does riot yet require access to them.

As to the possibilities of the airship in warfare, except for purposes of reconnaissance, Professor Newcojib is brief and emphatic. The flyer is out of the question as an agent of destruction or anything else. The airship's vulnerability is obvious. "A single yeoman armed with a repeating rifle could disable a whole fleet of airships . . . before the crews could even see wliero he was." The airship must, therefore, operate beyond tho range of earth-fire, and this involves an altitude of two miles. They cannot usefully seek to do anything but drop explosivo bombs into fortifications or. warships, and anyone can realise the difficulty, almost the impossibility, of dropping a bomb from a swaying airship so as to strike a moving, or even a stationary, mark, two miles bolow and thirty seconds later. Professor Newcomb declares that he has seen no evidence that any writer or projector has ever really weighed the considerations which he adduces. His conclusions aro these:—

"We have not dwelt upon tho great ratio of failure to success or of labour cost to results in tho trials hitherto made. . . .

Wo have_ allowed no practical questions of construction to interiors with success. We have shown what would be tho moro than colossal dimensions of an airship that could successfully compete with tho ocean steamship of, to-day, without inquiring into tho practicability of building her or the problem of managing her in an ocean storm. May wo not say, as tho outcome of these reflections, that the efforts at aerial navigation now being mado are simply most ingenious attempts to substitute, as a support of moving bodies, tho thin air for tho solid ground ? And is it not evident, on careful consideration, that the ground aifords a much better baso than air ever can? , . . The glamour which surrounds tho idea of flying through the air is the result of ancestral notions, implanted in the minds of our raco before steam transportation had attained its present development. Exceptional cases there may bo in which the airship will servo a purpose, but they are fow and unimportant. - ' It will be interesting! to see what reply the experimenters, who, to say the truth, are generally falling out of their machines or weeping at their destruction, will say to the calm arguments of this famous scientist.