Lucky Jim and TwinkletoeLUCKY JIM AND TWINKLETOE, THE MASCOTS
LUCKY JIM AND TWINKLETOE, THE MASCOTS
LUCKY JIM AND TWINKLETOE, THE MASCOTS
The flight ended with a crachTHE TRANSATLANTIC FLIGHT ENDED WITH A CRASH IN AN IRISH BOG
THE TRANSATLANTIC FLIGHT ENDED WITH A CRASH IN AN IRISH BOG
THE TRANSATLANTIC FLIGHT ENDED WITH A CRASH IN AN IRISH BOG
The projected airship of three million, five hundred thousand cubic feet capacity is capable of carrying a useful load of fifteen tons (passengers and mails) for a distance of forty-eight hundred miles in eighty hours, at the normal cruising speed. The total lifting power is one hundred and five tons, and the disposable lift (available for fuel, oil, stores, crew, passengers and freight) is sixty-eight tons. The maximumengine power is thirty-five hundred h. p., the maximum speed seventy-five miles an hour. The normal flying speed, using a cruising power of two thousand h. p., is sixty miles an hour. The overall length is eight hundred feet, the maximum diameter and width one hundred feet, and the overall height one hundred and five feet. These particulars and performances are based on present design, and on the results attained with ships of two million cubic feet capacity, now in service. The figures are conservative, and it is probable that a disposable lift greater than that of the specifications will be obtained as a result of improved structural efficiency.
The passenger accommodation will be such that the air journey can be made in comfort equal to that on a first-class liner of the sea. Apart from their comparatively small disposable lift, a main objection to vessels of theR-34type for commercial purposes is that the living quarters are in cars slung from under the middle envelope. In this position they are necessarily rather cramped. In the proposed craft of three million, five hundred thousand cubic feet capacity the passengers' quarters are at the top of the vessel. There, they will be roomyand entirely free from the vibration of the engines. They are reached through an internal corridor across the length of the ship, or by elevator, from the bottom of it.
The main room is a large saloon lounge fitted with tables and chairs in the style of a Pullman car. Around it are windows, allowing for daylight and for an outlook in every direction. Part of it is fire-proofed, and serves as a smoking room.
Next to, and communicating with, the lounge is the dining saloon. This leads to a serving hatch and electrical cooking apparatus. Electrical power is provided by dynamos driven off the main engines. Current for electric lighting and heating of the saloons, cars and sleeping quarters is provided by the same method.
Sleeping accommodation is in four-berth and two-berth cabins on top of the airship and forward of the living saloons. The cabins are of the type and size fitted on ocean-going steamers. With them are the usual bathrooms and offices. Other conveniences are an open shelter deck at the vessel's aft end, to enable passengers to take the air, and an observation car, fitted below the hull and also at the aft end, so that they can observe the land or sea directly below them.
No danger from fire need be feared. The machinery installation is carefully insulated from the gas bags, and the quarters are to be rendered fire-proof and gas-proof. Moreover, the amount of weight involved by the passengers' section is so small, compared with the weight of the machinery, fuel, cargo and stores, carried in the lower part of the craft, that the stability of the ship for rolling is unaffected by the novel position of the living quarters.
The ship's officers will have on the hull, towards the forward end, a control and navigation compartment, containing the main controls, navigation instruments, charts, and a cabin for the wireless telegraphy installation. The windows of this car give a clear view in every direction.
Other general specifications are:
Hull Structure.—The shape of the hull is of the most perfect stream-line form within the limitations of constructional requirements. An internal keel corridor, running along the bottom of the hull, contains all petrol and oil tanks and the water ballast.
Outer Covering.—The outer cover is made of special weather-proof fabric, which gives the longest possible life. This fabric is as efficientas possible in insulating the gas from change of temperature, and thus avoids great variations in the lift.
Gasbags.—The gas capacity is divided up into gasbags made of suitable rubber-proofed cotton fabric, lined with gold-beaters' skins. Gasbags will be fitted to automatic relief valves and hand control maneuvering valves.
Machinery Cars.—Six machinery cars are provided, each containing one engine installation, with a direct-driven propeller fitted at the aft end. These compartments give the mechanics easy access to each of the six engines, and allow them to handle all parts of the machinery. Engine room telegraphs of the electrical type communicate between the forward compartment and each of the machinery cars.
Whereas the living quarters and the control compartment must be heated by electric radiators, arrangements can be made to warm the machinery cars by utilizing the exhaust heat. The transmission gear in two of the wing cars is to be fitted with reversing gear, so that the craft may be driven astern. So that passengers shall not be worried by the usual roar of the exhaust, special silencers will be fitted. The transmission gear is also so arranged that allunnecessary clamor from it may be avoided.
The engines run on gasoline fuel, but they have devices whereby they can be run alternatively on hydrogen gas. They are designed to develop their maximum power at a height of five thousand feet.
Telephones.—Telephone communication links all stations on the airship.
Landing Gear.—Inflated buffer landing bags of a special type are to be fitted underneath the Forward Control Compartment and underneath the two Aft Machinery Cars. These enable the airship to alight either on land or on the sea's surface.
Wireless Telegraphy.—A powerful wireless telegraphy installation is to be fitted in the wireless cabin in the forward control compartment. It will have a range for sending and receiving of at least five thousand miles.
Crew.—Two watches would be required, taking duty in eight-hour shifts. Both must be on duty when the craft leaves or lands. Each watch consists of navigating officer, steersman, elevator man, four engineers and a wireless operator. With the commanding officer and two stewards, whose duties are not regulated by watches, the crew thus numbers nineteen men.
Although the speed of the airship at maximum power is seventy miles per hour, the crossing normally would be made at sixty miles per hour, which only requires two thousand horse power, and is much more economical in fuel. The full speed, however, can be used whenever the ship is obliged to voyage through storm areas or against strong head winds. By the Azores route, the time needed for the journey of thirty-six hundred miles, at a speed of sixty miles per hour, is sixty hours; but to allow for delays owing to adverse weather, the airship would always carry eighty hours' fuel, allowing for a speed of sixty miles per hour. The normal time for the journey from London to New York, via Portugal and the Azores (thirty-six hundred miles) would be, therefore, two and one half days. The normal time for the journey New York to London by the direct route (three thousand miles) would be just over two days.
The prevailing wind on the direct route is almost always from West to East, which favors the Eastbound journey, but is unfavorable to the Westbound journey. It is proposed that the crossing Eastward from New York to London be made by the most direct route, advantage thus being taken of the Westerly winds.
By making the Westbound journey on the Southerly route, via the Coast of Portugal and the Azores, and on 35´ N. parallel of latitude across the Atlantic, and then to New York, the voyage is made in a region where the prevailing Westerly winds of the higher latitudes are absent, and only light winds are encountered, generally of a favorable direction. This route, however, adds about six hundred miles to the distance. With a ship speed of sixty miles per hour, it would be quicker to make the Westbound journey by the direct route if the Westerly wind did not exceed ten miles per hour. If the wind were greater, time would be saved by covering the extra six hundred miles of the Southerly route and dodging the unfavorable air currents.
With four airships on the Cross-Atlantic airway, two only would be in service at a time, so that each could lay up during alternate weeks for overhaul and re-fit. As the time of journey between London and New York will vary between fifty to sixty hours, each airship can easily make two crossings or one double journey per week, thus giving a service, with two dirigibles, of two "sailings" each way per week.
The average time table might therefore be as follows:
From available weather reports, it is considered that crossings are practicable on at least three hundred days in the year. Probably a total of two hundred crossings in the year could be maintained. Until further study of weather conditions supplies a certain knowledge of the best possible altitudes and latitudes, it is likely that a regular service of two crossings each way per week will be maintained only in the months of May to September, and that the crossings from October to April will be irregular, the day of departure being dependent on the weather.
Weather difficulties are likely to be much less severe than might be imagined. Rain, hail and snow should have little influence on the navigation of airships. An outer covering thatis rainproof and non-absorbent avoids the absorption of water and the consequent increase of weight. Hail and snow cannot adhere to the surface of the craft when in flight, owing to its high speed through the air; and, in any case, the precipitation height being not more than eight thousand feet, they can be avoided by flying above this altitude.
Fog may give trouble in landing, but during the journey an airship can keep above it. If the terminal were enveloped by fog an arriving ship could pass on to an emergency landing ground away from the fog-belt; if the mistiness were slight, it could remain in the air until the ground were visible, making use of its margin of fuel beyond the amount necessary for the London-New York flight. Airships in fog may be enabled to find their landing ground by means of captive balloons or kites, and of strong searchlights from the ground. At night, the balloons or kites could carry electric lights, with connections from the aërodrome.
In any case, fog, rain, hail and snow are nearly always local in their occurrence, and can be avoided by a short deviation from the usual route. Atlantic records indicate that on the main steamship routes fog sufficient to impedenavigation does not occur on more than about twelve days in the year.
Wind is a factor that needs more careful study in its relation to transatlantic air navigation. In most cases, unduly strong winds can be dodged by flying on a higher level, or by cruising on a different course, so as to avoid the storm belt. Heavy storms, which are usually of a cyclonic nature, rarely cover an area of more than two hundred miles diameter. Moreover, the rate of progression of a cyclonic area is much less than the speed of the air movement. An airship is able to shake off a cyclonic area by a deviation from its course of not more than two hundred miles. Once away from the storm belt, it has no difficulty in keeping clear of it.
When higher levels of the air have been charted, there is every reason to believe that the known movements of the Atlantic winds will be used to shorten air journeys. There are at sea level, between certain clearly defined latitudes, prevailing winds of constant direction. At greater heights, also, there is in most latitudes a constant drift which, if charted, might be useful even if winds at sea level were unfavorable.
Although precise information is available ofthe prevailing and periodic winds at sea level in various latitudes, very little coördinated work appears to have been done in charting the prevailing and seasonal winds in higher levels of the atmosphere. Observations of the air currents over various localities in the United States, England and Germany have been taken, but very little is known of the winds above the great ocean tracts. There is a great necessity for international research to provide data for predictions of weather conditions in the upper atmosphere and thus enable advantage to be taken of these higher currents.
At high altitudes, constant winds of from thirty to forty miles per hour are common. If the prevailing directions of those were known to airship navigators, the duration of the journey could be considerably shortened, even if this meant taking an indirect route. It is undesirable to fly at great heights owing to the low temperature; but with suitable provision for heating there is no reason why flying at ten thousand feet should not be common.
Air currents cannot be charted as exactly as sea currents; but much valuable work can and will be done by tabulating in detail, for the guidance of air navigators, the tendencies ofthe Atlantic atmospheric drifts. Reliable charts, used in conjunction with directional messages from wireless stations and ships, may make it possible for vessels on the London-New York air service always to avoid troublesome winds, as well as storms and fogs, and to reduce the percentage of risk to a figure not exceeding that relative to sea liners.
For the rest, the excellence of the most modern engines and the fact that one or two, or even three of them can be temporarily out of action without affecting the airship's stability during a flight, minimize the danger of a breakdown from loss of power. The only remaining obstacle to reasonable safety would seem to be in landing on and departing from the terminal during rough weather. This can be overcome by the recently patented Vickers Mooring Gear for Rigid Airships.
The gear, designed so as to permit an airship to land and remain moored in the open for extended periods in any weather without the use of sheds, consists principally of a tall steel mast or tower, about one hundred and fifty feet in height, with a revolving head to which the craft is rigidly attached by the nose, permitting it to ride clear of the ground and to turn round inaccordance with the direction of the wind. It is provided with a hauling-in winch and rope to bring the ship up to the mooring point.
An elevator, for passengers and goods, runs up the tower from the ground to the platform adjoining the nose of the airship. The passengers reach their quarters along a passage through the vessel, and the goods are taken down a runway. An airship moored to this mast can remain unharmed in even the worst weather, and need be taken into a shed only when overhaul and repairs are necessary.
In discussing the future of transatlantic flight I have confined myself to the projected service between London and New York. There is likely to be another route over the Atlantic—London to Rio de Janeiro, via Lisbon and Sierra Leone. Already in London tickets are on sale at $5,000 apiece for the first flight from London to Rio. This, of course, is a freak price, which covers the distinction of being in the first airship to travel from England to Brazil. If and when a regular London-Rio service is established, the ordinary passenger rate should be little more than the $240 estimated as the air fare on the London-New York route.
It may be that the London-New York air service will not arrive for many years. Sooner or later, however, it must arrive; for science, allied to human enterprise, never neglects a big idea. It may be that, when it does arrive, the structure of the craft and the methods of navigation applied to them will differ in important details from what I have indicated. I make no pretense at prophecy, but have merely tried to show how, with the means already at hand, moderately priced air journeys from Europe to America can be made in two to two and a half days, with comfort, safety and a high degree of reliability. Meanwhile, much depends on the funds available for the erection of stations for directional wireless messages, on research into the air currents at various levels above the Atlantic Ocean, on the courage of capitalists in promoting what seems to be a very speculative enterprise, and on new adaptations of old mechanical inventions.
Already hundreds of aëroplanes, as time-saving vehicles, are used regularly in many countries for commercial traffic over comparatively short distances—the carriage of mails, passengers, valuable freight and urgent special journeys.When, but not until, the hundreds become thousands, and the longer distances are as well served by airships as are the shorter distances by aëroplanes, the world's air age will be in sight.
[1]For airships with gross gas capacity of 3,500,000 cubic feet and total load of 105 tons.
[1]For airships with gross gas capacity of 3,500,000 cubic feet and total load of 105 tons.
[2]For machines with total load of 40 tons.
[2]For machines with total load of 40 tons.
Although facts disappointed many over-sanguine expectations that the billions of dollars invested in aëronautics during the war would pay direct dividends already in 1919, the year brought us a long step nearer the age of universal flight. Meantime, commercial aviation is still a long way from the stage at which bankers regard its undertakings as good security for loans.
Chart of the North AtlanticCHART OF THE NORTH ATLANTIC SHOWING COURSE OF THE FLIGHT
CHART OF THE NORTH ATLANTIC SHOWING COURSE OF THE FLIGHT
CHART OF THE NORTH ATLANTIC SHOWING COURSE OF THE FLIGHT
The men who workedTHE MEN WHO WORKED WITHOUT GLORY TO MAKE THE FLIGHT POSSIBLE
THE MEN WHO WORKED WITHOUT GLORY TO MAKE THE FLIGHT POSSIBLE
THE MEN WHO WORKED WITHOUT GLORY TO MAKE THE FLIGHT POSSIBLE
Air routes have been opened up in most parts of the world. Captain Ross-Smith has shown, by his magnificent journey from England to Australia in a Vickers-Vimy aëroplane, that long-distance flights over the most out-of-the-way lands and ocean tracts can be made even under the present unsatisfactory conditions, before terminals, landing grounds and wireless stations are provided for air pilots and navigators. The Atlantic has been crossed four times, twice by a dirigible, once by an aëroplane andonce by a flying boat. Aëroplanes have flown from England to India. Aircraft have been used for commercial purposes in every part of Western Europe, in most countries of North and South America, in Australia, India, Egypt and South Africa. Important exhibitions of modern aircraft, similar to automobile shows, have been held in London, New York, Paris, Amsterdam and elsewhere.
To-day all the Great Powers can show commercial air services in full operation. Of these the most important are perhaps the triangular airways around London, Paris and Brussels. One French and two British companies operate daily between London and Paris; British craft travel backwards and forwards between London and Brussels three times a week; and French machines fly between Paris and Brussels every day.
The London-Paris services have established a magnificent record for efficiency and regularity. Valuable and urgent freight of every kind, including furs, dresses, jewelry, documents, a bunch of keys, perfume, a grand piano and even a consignment of lobsters, have been delivered in safety. Forty pounds of assorted London newspapers are taken each morning to Paris,where they are sold in the streets on the day of publication instead of next morning, as was the case when they were forwarded by train and packet-boat. Leading London papers, such as theTimes, theTelegraph, theMorning Post, theDaily Mail, and theDaily Express, have regular contracts with one of the companies.
As for passengers, men of every occupation take advantage of the opportunity to travel comfortably from London to Paris in two and one-quarter hours. There is seldom a vacant seat on the larger machines; although the fare is at present rather high, ranging from $75 to $105 for the single journey.
Moreover, the accommodation on two of the types of aëroplane now used—the Handley-PageW-8and the AircoDH-18—is more attractive than that of a Pullman car. The Handley-PageW-8carries fifteen to twenty passengers with personal luggage, or two tons of freight. The AircoDH-18takes eight passengers, with their personal luggage.
The past year saw no specially important developments of commercial aviation inside Great Britain itself. A week-end service between Southampton and Havre was inaugurated, and passengers and mails were flown from Londonto Leeds. The most important undertaking was perhaps the delivery by air of newspapers. For a time the Manchester edition of theDaily Mailwas taken by air for distribution in Carlisle, Dundee and Aberdeen, the last-named place being reached in three and one-quarter hours instead of the thirteen hours of train journey. Evening newspapers were carried daily during the summer from London to various resorts on the South coast.
The London-Leeds undertaking is the only regular service between English towns that has lasted for long. Elsewhere the air rates proved to be too high, and although there were plenty of aërodromes, the promoters of aërial transport companies could not compete with the all-embracing network of railways. During the great railway strike of October, however, valuable transport work was done by aircraft. For the rest, aëroplanes in England are chartered as aërial taxicabs for special trips, and last summer one or two companies reaped a moderate harvest by organizing pleasure trips at the seaside resorts. An airship or two have taken tours around the battlefields of France and Flanders. A few wealthy amateurs have bought aëroplanes for their private use.
Other European countries—France, Italy, Holland, Belgium, Scandinavia, Spain and Portugal—have made rather less progress in the manufacture and development of aëroplanes or dirigibles; but their use of aircraft for commercial purposes was about the same as that of Britain—newspaper distribution, some special journeys, and many joyrides. French aviators have opened tentative airways to Morocco, Senegal and Tunis. For regular passenger or goods services in continental Europe the high cost of fuel and accessories makes the rates too high. Also aërodromes and landing grounds are too few; and seldom can aëroplanes compete on a large scale with railways over comparatively short distances. Exceptions are the Paris-Lyons and Madrid-Lisbon airways.
Germany, throughout what was for her a terrible year, made further progress with her Zeppelin dirigibles. A number of return voyages were made over the route Berlin-Munich-Vienna-Constantinople. The latest type of Zeppelin is so efficient that no weather conditions, except a strong cross-hangar wind, prevents the airshipBodenseefrom making its daily flight of three hundred and ninety miles between Friedrichshafen and Staalsen, thirteen miles fromBerlin. The passenger carrying Zeppelins, which prior to the war provided the only important example of commercial aircraft, claim a remarkable record. They have carried more than one hundred and forty thousand people, and yet not one of the passengers has been killed or injured in an accident; although some members of the crews lost their lives in the early days of the pioneer Zeppelins.
The vast distances of the United States offer better opportunities for aëroplane traffic than the comparatively small and closely-railwayed countries of Western Europe. There is no doubt that, had the United States government supported its aircraft companies to the same extent as did the British government, commercial aviation in America would have traveled along a smooth road. Even without this support it has made excellent progress. Successful regular services are established between Los Angeles and San Diego, and elsewhere in the West, and in the East many passengers have been carried between New York and Atlantic City, and around the coast of Florida. Plans are being laid for various other airways, including one between Key West and Havana.
While no continuous service for aërial goodstraffic exist in the United States, aëroplanes are often chartered for special deliveries. This is particularly the case in the oil countries of Texas and Oklahoma, where newly-grown and important centers are off the beaten railroad track. One company in Oklahoma regularly sends its employees' pay by aëroplane from town to oilfield camp, thus assuring a quick and safe delivery, free from the necessity of armed guards and the danger of hold-ups. Other items worth noting in the United States' aërial history of the past twelve months are that aëroplanes have performed survey work and located forest fires, that thirty-two cities have applied for commercial aërodromes for postal, passenger and express purposes, and that an advertising agency is soliciting aërial business that will include display work on dirigibles, balloons and aëroplanes, the dropping of pamphlets from the air, and aërial photography.
Where the United States undoubtedly leads the way is in the ownership and use of privately owned aëroplanes—a circumstance partly explained by the great quantities of new money being spent. For a time some of the American manufacturers were months behind their post-war orders, and were selling everything thatcould fly. One famous company disposed of hundreds of pleasure craft at $7,500 apiece. Many buyers, impatient of delay, accepted immediate delivery of training machines, rather than wait for the pleasure craft. Reputable agencies dealing in second-hand aëroplanes bought from the United States and Canadian governments, disposed of thousands of machines and could not obtain enough to satisfy all their clients. An interesting development was the idea of community aëroplanes, purchased and maintained jointly by small groups of people living in the same residential district.
The United States postal authorities have satisfactorily maintained aërial mail services over the route New York-Washington-Cleveland-Chicago. After some preliminary fiascos these became reliable, besides being very speedy, as compared with train schedules. For June the Washington-New York air mail achieved ninety-nine per cent. efficiency, and the Cleveland-Chicago route one hundred per cent. The latter never missed a day in May and June, and not a single forced landing occurred during the first seventy days. At the close of 1919 the air mails showed a surplus of $19,000 of revenue over working costs, on a basis of twocents charge for each ounce of mail matter carried. Better results are expected now that specially constructed machines, with freight capacities of one thousand pounds and upward, are ready for use.
The British dominions and dependencies take a great interest in aëronautics, and last year saw satisfactory beginnings in some of them. In Australia, for example, a passenger and freight service links Sydney and Port Darwin, over a distance of twenty-five hundred miles, with intervening stations. Plans are ready for regular flights from North to South of the continent, and also from East to West, across the difficult country between New South Wales and Victoria on the one hand, and Western Australia on the other.
Canada has found a highly successful use for aëroplanes in prospecting the Labrador timber country. A group of machines returned from an exploration with valuable photographs and maps of hundreds of thousands of dollars' worth of forest land. Aërial fire patrols, also, have been sent out over the forests. While no important air route for passenger carrying is yet utilized in Canada, there is a certain amount of private flying, and air journeys for businesspurposes are common. Plans have been prepared for a regular service between Newfoundland and cities on the mainland, thus saving many hours over the time schedules perpetrated by the little Newfoundland railway.
In the South African Union, where the railway system by no means corresponds with the vast distances, many passengers and mails are carried by air from Johannesburg to Pretoria, Maritzburg, Durban and Cape Town. Later, when the services over these routes are better organized, they will doubtless be extended to important centers in Rhodesia, the East Africas and what was German South-West Africa.
Aëroplanes in India take passengers over the route Calcutta-Simla in twelve to fourteen hours of cool roominess, as compared with forty-two hours of stuffy oppressiveness on a train. Other Indian air routes in preparation are Calcutta-Bombay, Calcutta-Darjeeling and Calcutta-Puri. The air fare in India averages about 11 cents a mile.
Aërodromes and landing grounds are already prepared between Egypt and India, and several machines have made the journey from Cairo to Delhi, via Damascus, the Syrian Desert, Bagdad, Bandar Abbas and Karachi. Elsewherein the East—the Malay Peninsula, Singapore, Borneo, Java and China—similar routes are planned. The whole of Eastern Africa, from Cairo to Cape Town, has been mapped out for the use of aircraft, with landing grounds at short intervals.
So much for accomplishment during the past year. What the future and the near-future have in store for aëronautics is problematical, and any detailed analysis must be conjecture. The general trend of development during the next two years may be forecast, however, with a fair degree of accuracy.
Anybody who blends sane imagination with some knowledge of the history of aëronautics must realize that what has been achieved is very little in comparison with what can be achieved. It is unnecessary to make trite comparisons with the first stages of steam locomotives or motor cars.
Yet, it is folly to expect an air age now. Its coming will be delayed by the necessity of slow, painstaking research, and by the fact that in the countries which are encouraging aviation to the greatest degree, capital is no longer fluid and plentiful, and money in substantial sums cannot be risked on magnificent experiments. Thecost of building fleets of dirigibles and hosts of air terminals, for example, must be enormous; and until it has been demonstrated beyond question that they will be paying propositions, financiers and investors are unlikely to be interested in their concrete possibilities on a large scale.
Unless some startling innovation—a much cheaper fuel for example, or a successful helicopter—revolutionizes commercial aviation, its near-future is unlikely to stray beyond the extension of airways over distances of about five hundred to two thousand miles. These are likely to be covered mostly by heavier-than-air craft, although, as in Germany, dirigibles will have their place.
Extension of air traffic is especially probable in industrial and agricultural countries of large area, such as the United States, Canada, Australia, India and the South American republics. Another projected development with immediate possibilities is the linking of regions that are separated by a comparatively narrow expanse of water. Obvious examples, in addition to Britain and France, are England and Ireland, the Mediterranean coast of France and the Mediterranean coast of Africa, and Florida and Cuba.
Traffic across the ocean or a great lake offers to air travel the best time-saving inducement. To connect two places separated by one hundred and fifty miles of water, an average steamship needs ten hours. A passenger on it must spend at least one night away from home, while transacting his business. An air passenger covers the same distance in one and one-half to two hours, and can return on the same day. For such transport the seaplane and the flying boat will have their chance.
Besides the carriage of passengers, mails and valuable freight, aviation will have many additional functions. Maps may be made and checked with absolute accuracy by means of aërial photography. Another important function of the aëroplane and the aërial camera is to explore and prospect undeveloped districts. In places remote from the ordinary facilities of civilization aircraft may be used for the discovery of fire, flood and lawlessness. Already the Canadian Northwest Mounted Police have captured wrongdoers by means of aëroplane patrols.
Aircraft offer particular advantages as carriers in regions where the natural obstacles on the ground prohibit railway or road transport.In Alaska valuable metals and furs are brought to civilization on sleds drawn by dogs, over paths that are circuitous and dangerous. They could be taken in safety, and with an immense saving of time, by aëroplanes fitted with skids suitable for landing on ice and snow. Again, copper is transported from mines in the Andes by llamas, which are slow and must jog over devious tracks. Aëroplanes could make the journey directly and speedily, from mine to coast, without regard to precipice, marsh or forest.
South America is likely to be a happy hunting-ground for aëronautical pioneers. The mountain-range of the Andes, which for hundreds of miles sharply divides America into two parts, gives aviation an incontestable opportunity. The eastern section of South America could be brought days nearer the western section by high-climbing aircraft, which would provide a pleasant alternative to the roundabout, uncomfortable journeying now necessary. The air mails between the two great commercial centers of South America—Rio de Janeiro and Buenos Ayres—should also save many days of valuable time. Many owners of ranches andplantations in the Argentine, Uruguay, Paraguay and Brazil are buying aëroplanes to bring their isolated, up-country properties in closer contact with the towns.
Asia and Africa have similar geographical problems, to which air traffic might find a ready solution. Each of these continents has enormous areas that, because of the absence of good railways, are either unproductive or much less productive than their resources warrant. A few of many such cases are Turkestan, Central Arabia, parts of China, Siberia, Thibet, and the whole of Central Africa. Most of these are rich in minerals. Meanwhile, aëroplanes have flown between the desert marts of Damascus and Bagdad in eight to ten hours. These cities are not yet linked by railroad and a camel caravan over the Syrian desert covers the same route in two weeks to a month. The same conditions apply to the Gobi desert.
So far I have dealt with the future of commercial aëronautics almost entirely in terms of heavier-than-air machines. These—land planes, seaplanes and flying boats—have at present a useful radius of non-stop flight confined to distances of under one thousand miles. The limitation must remain until changes in the basicprinciples of aëroplane construction are so altered as to give a much greater speed in proportion to fuel consumption. One such change may be the introduction of wings with variable camber. This, by permitting variations in the angle of incidence, would make possible a quick ascent at a steep inclination, and a very fast forward speed once the required height had been attained. The benefits from variable camber could be increased by the introduction of a propeller with a variable pitch. Going still further in the same direction, we may find any day that one of the attempts in various countries to design and construct a successful helicopter has matured, producing a machine which, by reason of a very powerful propeller on a moveable shaft that can be inclined in any direction, will not only rise and descend vertically, but also may be made to travel forward at a great speed and to perform such acrobatic tricks as sudden halts, retreats and jumps.
All this, however, is surmise; and we are faced with the fact that until the design of aëroplanes differs radically from its present form, heavier-than-air flying apparatuses are limited as to maximum size by certain structural principles too complicated for explanation in this non-technical analysis. A further limitation isimposed by the space needed by the largest machines for leaving the ground or landing.
Within these bounds it has been found that the maximum capacity for passengers and freight does not greatly exceed one and one-half to two tons for a non-stop journey of five hundred miles in still air. Lesser distances do not increase the useful load appreciably, but greater distances decrease it; until for a radius of about twenty-five hundred miles the whole of the disposable lift is needed for fuel, and nothing else may be carried.
For long journeys over land, therefore, the aëroplane must come to earth for replenishment of fuel every five hundred miles. Even for this distance it cannot take more than one and one-half to two tons beyond the weight of fuel and crew. If heavier loads are to be transported, more machines must be used. Finally there comes a point at which a single airship, carrying a heavy freight over five hundred miles, is more economical than several aëroplanes. For non-stop flights of over one thousand miles the same considerations make the airship always more economical than the aëroplane.
Over the ocean the flying boat can beat the dirigible in time and cost up to five hundredmiles. Even at one thousand miles it is a commercial proposition, but it must then have all in its favor. For longer distances the airship has no competitor. It may be deduced that in years to come, when the world's airways are in general operation, heavier-than-air machines will bring freight to the great airports, there to be transferred to dirigibles and by them carried to the earth's uttermost ends.
The time for this seeming Utopia is not yet, however, although a group of airship interests in England are now planning airship services that may eventually set London within two and a half days of New York, one and a half days of Cairo, four of Rio de Janeiro, five and a half of Cape Town and seven of Australia. But first must come bold expenditure, very careful organization, many-sided research and improved invention.
Although no claim is made that present-day airships can compete for reliability with railroad trains and ocean liners, there is no doubt that a sufficient number of passengers are prepared to pay relatively higher rates for the great saving in time taken for long distance journeys, particularly over the ocean.
The demand would be mainly for the carriage of express freight and mail matter and for passenger traffic to serve people who wish to get from center to center in the shortest possible time. Another use for large airships would be the carrying of freight of high intrinsic value, such as valuable ores, from places otherwise inaccessible, or not provided with other means of direct transport.
To meet the requirements of various purposes for which airships may be utilized, dirigibles of four kinds are projected:
First, the airship of moderate size and high speed for carrying express, mails and passengers.
Secondly, the air liner solely for passenger traffic, of a large size and speed.
Thirdly, the large airship of comparatively slow speed, and great carrying capacity, for general transport.
Fourthly, the small non-rigid airship for private purchase and upkeep as an aërial yacht.
Aeroplane worksTHE VICKERS AEROPLANE WORKS AT WEYBRIDGE, ENGLAND
THE VICKERS AEROPLANE WORKS AT WEYBRIDGE, ENGLAND
THE VICKERS AEROPLANE WORKS AT WEYBRIDGE, ENGLAND
Air travel comfortCOMFORT CAN BE ENJOYED IN AIR TRAVEL TO-DAY
COMFORT CAN BE ENJOYED IN AIR TRAVEL TO-DAY
COMFORT CAN BE ENJOYED IN AIR TRAVEL TO-DAY
The rigid airship is as yet only at the beginning of its development, particularly as regards size and carrying capacity. The airship of three million, five hundred thousand cubic feet capacity, for immediate use on the fast passenger services, carrying a load of passengers offifteen tons for a distance of forty-eight hundred miles, might be built immediately, and could be housed in sheds at present available. As the lift and speed efficiency of a rigid airship increases rapidly in proportion to the vessel's size, it will be advantageous to use the largest airships that can be economically operated. A rigid dirigible able to carry fifty tons of passengers and freight for ten thousand miles at a speed of eighty miles an hour is quite feasible; and the design and construction of such an airship could be undertaken immediately if it were justified by the demand for air transport.
The ships of three million, five hundred thousand cubic feet capacity, which can be housed and flown for commercial purposes as soon as the required terminals and navigational facilities are ready, will approximate to those described as being suitable for a transatlantic service. If standardized for adaptation to all conditions and world routes, they should be capable of a non-stop flight of about eighty hours, at an average speed of sixty miles an hour.
To prevent wastage and reduce the running costs, several economical devices for dealingwith height equilibrium are needed. On long flights the greatest problems are maintenance of the airship at a constant height, and avoidance of the loss of gas consequent on expansion when the ship rises as it loses weight by the consumption of fuel. Owing to the great variation in temperature between day and night, the ship becomes heavy at night owing to the lower temperature, and light during the day, as a result of the higher temperature. A discharge of ballast at nightfall, and of gas in the morning, is needed to keep it in equilibrium. To obviate discharge of gas, and the necessity of starting with a large weight of ballast, it is proposed to run a proportion of the engines on hydrogen fuel, so that the hydrogen can be consumed at such a rate that the loss of lift equals the loss of weight of fuel consumed by the other engines, thus economically using hydrogen which otherwise would be lost through the discharge of the gas valves.
I make the supposition that hydrogen, and not helium, will be the sustaining gas. For commercial aviation it has many advantages, for helium is dearer and rarer, and has about twenty per cent. less lift. Contrary to general belief, a flight in an airship filled with hydrogen,subject to proper precautions, has no greater fire risk than living near a gas factory. Helium is a necessity only for airships used in war, as, unlike hydrogen, it is not ignited by incendiary bullets from hostile aircraft. The United States has almost a monopoly of the world's quantitative supply of helium, which fact should be a tremendous asset in wartime.
The ballast difficulty can be met by apparatus to condense the water of combustion from the exhaust gases of the engines. Experiments have shown that it is practicable to recover water of slightly greater weight than the gasoline fuel consumed, thus avoiding any variation in lift due to gasoline consumption. Further, water ballast could be picked up periodically from the sea by descending and taking in water through a pump suspended from a flexible hose, or direct into tanks in the gondolas through sea-valves.
Still further reduction of running costs may be effected by fuel economy. This would be difficult with internal combustion engines of the type in use at present, for greater thermal efficiency (the ratio between the amount of heat contained in the fuel consumed and the amountof useful work delivered by the engine) necessitates heavier machinery. The reduction in gasoline consumption is thus offset by a decrease in the disposable lift. It is probable that a saving on large dirigibles might result from substituting for the internal combustion method of generating power engines that burn cheap oils. Although such engines are much heavier, and although the crude oils weigh a good deal more than gasoline, the difference would be more than covered on long flights, for gasoline is nearly four times dearer than crude oil. Moreover, the weight of oil actually consumed would be about twenty per cent. less than that of the gasoline burned by internal combustion engines over the same distance.
The solution may be in the employment of steam. For the rather low standards of horsepower on which dirigibles are driven, heavy steam engines of the ordinary type, although much more reliable, would be less economical than internal combustion engines, owing to the latter's better thermal efficiency. Engineers are attempting to evolve a light type of steam turbine that will overcome this drawback.
Of equal importance to fuel economy is a better system of airship navigation. This is similar in principle to steamship navigation, but itis made more complicated by the much greater drift of atmospheric currents. Moreover, air currents can never be charted as exactly as sea currents. An excellent meteorological organization, for reporting motions of the air at given times, is therefore essential.
When flying over land a navigator can determine the drift of his vessel by taking observation on a suitable fixed point on the earth's surface, and adjusting his compass course accordingly. It is probable that a gyroscopic compass will be the standard type for dirigibles. Many aviators have experienced difficulties with the magnetic compass on long flights; although it has served me well always, especially on my transatlantic flight as Captain Alcock's navigator.
Over the sea no fixed point is available, so that the motion of the wind must be checked periodically. One method is for the navigator to make astronomical observations, and from them deduce his position on the chart. Another may be the use of bombs which ignite on the water and give out a dense smoke or a bright light, lasting for several minutes. During the day the navigator sights on the smoke, and during the night on the light, and thus discoversthe wind's velocity and direction. An invention that could simplify navigation would be some form of ground-speed meter, showing at a glance the rate of progress over the earth (as distinct from air speed), with either a following or a contrary wind.
The most valuable means of airship navigation will be that of directional wireless. Communication from two separate stations, which could be either land terminals or stationary ships in the ocean, gives the direction of the transmitted wireless waves and signals to the dirigible its bearings. The position is then laid off on the chart, and the course regulated accordingly. This method was used by the German Zeppelins during the war.
Of equal importance to the structural and navigational equipment of airships is the provision of suitable terminals for each route. These would require, among other necessities, an aërodrome of about one mile square; a double airship shed capable of housing two vessels; a mooring-out tower; mechanical gear for transferring an airship from the mooring tower to the shed; hydrogen generating and storage plant; repair workshops and stores; meteorological offices; wireless telegraphy installation;electrical night signaling and landing arrangements; a station on the local railway from the main part of the city; a hotel; a garage; and customs and booking offices.
The aërodrome must be a short distance from the city served by the airship service. If possible it should be near a chemical works where hydrogen could be produced as a by-product. The ground would be preferably on a site remote from hills and other topographical features likely to cause air disturbances.
The double sheds for housing vessels of the size specified, three million, five hundred thousand cubic feet capacity, would have two berths, the minimum dimensions of each of which must be eight hundred and fifty feet long, one hundred and fifty feet wide, and one hundred and fifteen feet high. Their contents should include hydrogen filling mains and gear for slinging the airships from the roof when deflated for overhaul. Special arrangements would be made for rapid replenishment of the ships with gas, fuel, and water ballast.
If no industrial supply of hydrogen were provided by a nearby factory, the aërodrome should have a generating plant capable of producing fifty thousand cubic feet of hydrogen perhour. Gasometer storage, with a capacity of about five hundred thousand cubic feet, is also a necessity.
The meteorological office would issue weather reports for the guidance of airship navigators, and issue navigating instructions to them by means of the wireless installation. The latter should have a range of at least five thousand miles.
Each aërodrome would be provided with suitable electric light signals to indicate the position of the landing ground to incoming ships at night, as well as landing lights to point the way to the mooring tower. Trolleys running on guide rails, with electrically driven gear, could move a dirigible from the tower to the shed with a minimum of man power.
A suitable mooring tower constitutes an enormous saving of time and labor. The Vickers Patent Mooring Gear, which has been tested satisfactorily, can be worked by half a dozen men; whereas the old method of rope pulling and dragging needs two to four hundred men for landing an airship of three million, five hundred thousand cubic feet capacity.
With existing methods, a rigid airship must be housed in a suitable shed when not in flight.The danger and difficulty of removing the ship from its shed, and returning it safely thereto after a journey, restricts the number of actual flying days in the year to those on which such operations can be performed without risk of damage, although a modern rigid airship may be in the air with efficiency and perfect safety in practically any state of the weather. The Patent Mooring Gear renders the landing independent of the weather, while calling for the attendance of only six men to actuate the various mechanical devices employed.
In principle, the gear consists of a tall steel mast, of such a height that when the ship is attached by the nose it rides on an even keel at a height of upwards of one hundred feet. The mast has at the top a platform or deck. The head of the tower is entirely enclosed and contains the necessary apparatus for bringing a vessel to rest. This top portion is designed to rotate, so that a ship, when moored, may always lie directly head to wind.
Access to the upper deck of the masthead is obtained by means of an elevator, which allows passengers to enter the ship in comfort. Behind the deck is a compartment containing the landing gear. This consists of an electricallydriven winding engine, fitted with about one thousand feet of the highest quality flexible steel wire rope, together with any automatic coupling. In the compartment are also pipes for the supply to the ship of hydrogen, gasoline, oil and water from the main reservoirs, situated on the ground at the foot of the mast. The vessel itself is fitted with apparatus complementary to that housed in the masthead. From the nose projects the attachment which is gripped by the automatic coupling, while in the bow is situated a storage drum and winch for six hundred feet of wire rope.
On approaching the aërodrome, the ship wirelesses its intention to land. The masthead mooring rope is then threaded through the automatic coupling, and paid out until the free end reaches the ground below. This end of the rope is attached by a shackle to the rear of a light car, which is driven away from the mast in the direction from which the ship is approaching, while the rope uncoils from the drum above. When at a distance of seven hundred or eight hundred feet from the foot of the mast the men in charge of the gear unshackle the rope, and spread landing signs that indicate to the airship pilot their position on the ground.
On arrival over the landing party, the ship's bow mooring rope is released, and runs out from the bow attachment under the influence of a weight of several hundred pounds in the form of sandbags. Two men of the party on the ground below take charge of the rope, unshackle the sandbags, and effect a junction with the mooring mast rope, which is in the hands of the remaining men of the landing party. The rope ends are coupled together by means of a self-locking coupling, which enables the junction to be made within five seconds.
The dirigible is now connected with the head of the mooring mast by a long length of steel wire rope. On receiving a signal from the ground party, the men in charge of the winding gear in the masthead haul in. As the rope tautens, ballast is discharged from the ship, which is slowly hauled into connection with the automatic coupling already set in the open position to receive the attachment on the nose. When once this coupling is closed, the mooring ropes can be dispensed with, the ship's rope being re-wound on to the storage drum in the bows.
After landing at the masthead, connection is made with the hydrogen, gasoline, oil, and watermains, and fresh gas, fuel and water ballast are placed on board, so that the ship may be kept in trim during the discharge of cargo, and so the embarkation of passengers and stores be effected.
When all is ready to leave the masthead for flight, the pulling of a lever in the automatic coupling releases the ship. The latter then draws astern and upward, under the influence of the prevailing wind, until it is well clear of the landing station and can proceed on its course.
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 asmall 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 hadtime 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 riskin 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.
3. The establishment of international air rules, including signals, lights, methods of avoiding collisions and regulations for landing.
4. The recognition of the special treatment of army, navy and state machines when on duty for the state.
5. Recognition of the right to utilize all public aërodromes in other states, under a charge to be uniform for the aircraft of all nations, including the home nation.
6. Recognition of the right of crossing one country to another, with the privilege of landing, but under the reservation of the right of the state crossed to apply its local rules, and if necessary to force the landing of the visiting machines on signal.
7. Recognition of the principle of mutual indemnity to cover damages to persons or property due to aircraft—the state of the offending machine to make reparation and then to recoup itself in any way it sees fit.
8. Recognition of the necessity of a permanent international aëronautical commission, in order to keep the development of the legal side of aviation abreast of the development of the science itself.
9. Recognition of the obligation of each state to regulate its internal legislation along the lines of the clauses of the international agreement.
The main airways of the world are still hypothetical, but some of their main terminals, in relation to the centers of industry and population and the trade routes, will certainly be London, New York, San Francisco, Tokio, Delhi, Colombo, Cairo, Cape Town, and Rio de Janeiro. In particular London, New York, Cairo and Rio de Janeiro are fitted to be great junctions for air traffic. London is the logical distribution center for passengers and freight from North and South America bound for Continental Europe or the East. The New York terminal should link the transatlantic airwaysfrom Europe with the airways of North America. Rio de Janeiro should perform the same function for South America, and also be the center of seaplane traffic up the Amazon. Cairo is destined to be the junction for the air routes between Europe, Asia, Africa and Australia. From it dirigibles or aëroplanes may pass to India (via Damascus and Bagdad), to Cape Town (via Nairobi), to Australia (via Aden and Colombo, or Delhi and Singapore), and to London (via Algiers or some point in Southern Italy). Cairo is also likely to be an important base for seaplanes and flying boats plying up and down the tremendous waterways of the Nile and the Great Lakes.
The British Empire is especially bound up with the airways of the future. The geographical position of the Briton forces him to think in Imperial terms. In 1776 Great Britain lost her most valuable colonies largely because the Atlantic Ocean made adequate representation of the colonial interest physically impossible. Since that day cables, steamships and the wireless have helped to overcome the distances that separate the overseas dominions from the British Isles. Aircraft and well-organized British air routes should be the greatest step in the consolidation of the far-flung Empire.
To this end British official experts mapped out the stages of the aërial route to Australia from Egypt, via Damascus, Bagdad, Karachi, Delhi, Calcutta, Singapore and Sumatra. Although the successive landing grounds were not ready in time for Captain Ross-Smith's magnificent flight from England to Australia, the information and advice collected by the official surveyors were of inestimable value to him. It is noteworthy that nearly the whole of the proposed airway from Egypt to Australia is over British territory or the sea.
The same is true of the proposed route from Cairo to Cape Town. This was planned out very carefully by three parties of military aviators, who covered the whole length of civilized and uncivilized Africa in their search for landing grounds. The absorption of German East Africa by the South African Union makes an all British corridor for aircraft from Cairo to Cape Town, by way of Egypt, the Sudan, British East Africa, British Central Africa, German East Africa, Rhodesia, the Transvaal and Cape Colony. There is an alternative water route over the Nile, the Great Lakes, the Zambezi River and along the coast to Cape Town. Beingthe junction of the airways to India, Australia and South Africa, Egypt is destined to be the nerve center of an air-linked British Empire, just as the Suez Canal has been its jugular vein.
But the laying out of great air routes to the East and South does not complete Britain's plans. She must connect them up with London—a task which is much more complicated from the standpoint of high politics, because it involves routes over the territory of other nations. An aëroplane can fly from London to Cairo via Gibraltar without passing over foreign territory or foreign territorial waters. But the air route would be long and the aërodrome bases great distances apart, in comparison with the proposed land route of two thousand miles across France, down the length of Italy and Greece and across the Mediterranean to Cairo. Such a route necessitates an entente cordiale with the nations of Western Europe, and is one of the reasons why Great Britain can never contemplate easily a loosening of the bonds that now hold together the Allies of Western Europe.
The French, for their part, are also thinking of air routes in terms of their colonial possessions. For them the international situation ismuch the same as for the London-Cairo airway. French pilots need not fly over foreign territory to Algiers or Morocco. A long flight across the Mediterranean, or skirting the west coast of Spain, is a possibility. But Spanish territory is the logical corridor from France to Africa. It was over Spain that a trip was made from Toulouse to Casablanca, the eighteen hundred miles being covered in eleven hours of actual flying. The ordinary postal service takes six days. For direct aërial communication with Syria, also, France must have an entente with several intervening countries.
Not only will the aëroplane connect France more closely with Africa; it will likewise bind together the various sections of France's colonial territory in Africa, The Sahara Desert will become a less formidable obstacle to intercommunication. French pilots have made experimental flights over parts of the Sahara in a search for the best routes and landing places, as links in communication between Morocco and the Ivory Coast.
When technical progress and perfected organization place the world's main airways in operation, there will be enormous saving of time on the longer routes. The estimated timefor transatlantic flights from London to New York by the three million, five hundred thousand cubic feet dirigibles is two to two and one-half days, Other likely figures for various services are as follows:
At an average speed of sixty miles per hour, and with a stop of twelve hours at each station for re-fueling, the times taken would be
By train and mail steamer, the journey to Ceylon at present takes fifteen days, and to Australia over thirty days.