The design of this apparatus is such that the landing of an airship is as easy in a wind as in complete calm. With its help an airship can land in any speed of wind in which it is safe to fly. Should the wind be so high (over 60 or 70 miles per hour) that the vessel cannot reach a given mast, it will always be possible to learn by wireless the nearest station at which favorable conditions allow it to come down.
The release of the ship from the mast can take place in any wind-speed. Owing to the comparatively local nature of a big storm (storms are known not to cover districts greater than two hundred miles in diameter) the vessel, after slipping its moorings, is able to circumnavigate the disturbed area by making a small initial deviation from the true course.
A part of the aërodrome should be given over to aëroplanes, used for the bringing of mails and urgent freight from places distant from the terminal. Heavier-than-air machines, in fact, will be the veins leading to the great arteries of the world's air routes, operated by dirigibles. A strong searchlight, for the guidance of aëroplane pilots flying in fog, might be necessary. Given improved landing facilities, means might be found for them to coast down the searchlight, if the ground away from it were invisible. Another method of delivering mails, before leaving for a landing ground away from the fog belt, is to drop them, attached to a parachute. When the package reaches earth it can be located by an electric bell, which rings on impact and continues ringing.
The mail services of to-day, by railway and boat, can in many cases be greatly speeded up if part of a long journey be covered by aëroplane. A good instance is the route between Great Britain and South America. If a merchant in London posts three letters to correspondents in New York, Rio de Janeiro and Buenos Ayres respectively, he may have a reply from New York before the Brazil man has had time to read his communication, and four or five days before the man in the Argentine has received his. An aërial short cut to Dakar—already several machines have flown there from Paris—would lessen by six or seven days the transit time for mailbags sent from England to Rio de Janeiro or Buenos Ayres.
As long as the internal combustion engine is used in aëronautics, and mechanical failure is always a possibility to be reckoned with, the cost of maintaining aëroplane routes, even if they be only auxiliary to dirigible or steamship services, will be greatly swollen by the need of maintaining frequent landing grounds. Every ten miles would be an ideal interval for them; every twenty miles is a minimum for first-rate insurance against risk. From a height of five thousand feet, the probable average minimum elevation for commercial air navigation, a pilot can without difficulty cover a distance of five miles while planing down without the aid of motors. From ten thousand feet he can cover ten miles under the same conditions; so that at this height he would never be outside gliding distance of landing grounds prepared every twenty miles.
Given these safeguards, the element of risk in present day aviation is no greater than it was in the early days of railways and steamboats; and little, if any, greater than in modern motoring. Many people, possessing only a newspaper acquaintance with aërial affairs, still believe mechanical flight to be perilous. In exactly the same manner men shunned the infant steamboat, railway train, bicycle and motor-car. Yet, proportionately, the aëroplane and the dirigible are responsible for no more deaths than the train or the automobile. The seeming discrepancy is because so much attention is paid to air fatalities. Every week-end motor-car accidents cause scores of fatalities. Yet the death in harness of a single aviator produces more comment than all of these. Partly, no doubt, the intense horror with which humanity regards death by falling from a great height is due to its novelty among human experiences.
The airways of the world offer some pretty problems of international politics, involving commerce, rights of landing, customs duties, air smuggling, air traffic regulations and air laws. All these were dealt with in the International Aërial Commission at the Peace Conference, which agreed upon the following principles:
1. Recognition of the greatest possible freedom of aërial navigation, as far as that freedom of navigation is reconcilable with the principle of the sovereignty of each state in the air above its territory, with the security of the state affected, and in conformity with a strict enforcement of safety regulations.
2. Regulation under obligatory permits for pilots and other aëronautical personnel to be recognized mutually by the signatory states.