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The two big fying boats—the A-1070 and the A-4036-rose from the choppy waters of Hampton Roads exactly at 10 o'clock, March 12. They tied up to the buoys of the naval air station at Rockaway just as the naval guard struck five bells at 2.30 o'clock March 12.

The Aight was made for special reconnaissance work as well as to establish a record. It also gave to the navy officials valuable data in connection with the plans for the coming attempt to cross the Atlantic in a flying boat two and one-half times the size of the F-5-L's.

Each of the two boats carried a great quantity of photographic apparatus, and valuable photographs and moving pictures were taken during the flight. These are to be shown at the Aeronautical Exposition to-day by the photographic section of the United States Navy.

The A-1070 was piloted by Ensign Souther. As passengers she carried Lieutenant W. L. Richardson, chief of naval aviation photography; Ensigns Marbury and Morrow, Chief Mechanicians Sacks and Driceland and Radio Operator Bowman.

The A-4036 was piloted by Ensign Irvine, and her passengers were Ensigns Pulliam and Sinclair, Photographer Kramer, Mechanicians Nice and Bark and Wireless Operator Miller.

Wireless telegraph and telephone communication was maintained between the two ships and with the shore stations throughout the flight. Two homing pigeons, used by the navy, were also carried.-Baltimore Evening Sun, 13/3.

BIGGER AIRPLANE FOR OVERSEAS FLIGHT NOW BEING RUSHED AT NAVY'S FACTORY.-A type of naval airplane, which in point of size, power, and carrying capacity exceeds the N. C.-1, is now under construction at the Navy's League Island aircraft factory in Philadelphia, it became known yesterday when an aircraft designer, who had been at the factory, described its features in detail.

The designer, who would not consent to have his name made public, said that work on the plane was going on night and day in order to have it ready as soon as possible for the contemplated transatlantic flight. Officials of the navy's air service, he said, had great faith in the new flying boat, and believed it would accomplish a trip to Europe with little or no difficulty.

The design of the new super-airplane, which is known as Model T, is similar to the navy's F-5, now being shown at the Aeronautical Exposition in Madison Square Garden and the 69th Regiment Armory. It has an upper wing span of 250 feet, which is 124 feet more than the N. C.-I. The lower wing is 25 feet less. The length of the craft over all is 80 feet. The wings are 12 feet broad and 14 feet apart.

The motive power for the new naval airplane will be supplied by five Liberty motors of 400 horsepower each. Three will be tractors and two pushers.

Seventy-five passengers will be able to ride comfortably in the Model T, according to The Times informant, making ample allowance for tanks carrying sufficient gasoline and oil for a flight of 2000 miles. The N. C.-I, has carried 51 passengers on one of its trips. If the new Model T lives up to the hopes of its builders, it will establish a new passenger-carrying record.

Construction on the machine has progressed so rapidly that its completion is expected in the very near future, according to the aircraft designer who told of its details. He was unable to express himself more definitely as to the date of its completion, he said, because of the many unforeseen difficulties which arise in building airplanes of a new type. N. Y. Times, 2/3.

HELIUM.-“When the armistice was signed one of the experimental plants which had been operated at Fort Worth, Texas, had successfully

produced helium at the rate of 3000 or 4000 cubic feet per day, but as this production was far below what would be required for the needs of the War Department and the Navy Department, to say nothing of that of our Allies, it was determined to undertake production on a large scale, and for this purpose contracts were entered into by the Navy Department, acting for both the War and Navy Departments, for the construction of a plant at Fort Worth having a capacity ten or twelve times as great as the experimental plant from which helium had been produced.

The necessary machinery for equipping this plant is now nearing completion, and the buildings will soon be under construction.

" In order that the supply of this rare gas may be conserved contracts have been entered into with the owners of the wells supplying it, by which the use of this gas for domestic purposes will be limited to such an extent as to conserve it for a period varying from 10 to 20 years. The necessity of doing this will be evident from the fact that foreign governments have already shown the greatest interest in this gas and are making every effort to secure a supply of it. The importance of conserving it is so great, however, that officers of the War and Navy Departments believe that Congress should lose no time in enacting legislation which will secure to the government the sole control of all helium-bearing gas in this country.

In explanation of the great military value of the gas it is stated that one shot from an explosive bullet is sufficient to explode the hydrogenfilled balloon of any airship, while the same balloon filled with helium is absolutely safe from attack.

This was thoroughly demonstrated by the Navy Department before the signing of the armistice by conducting experiments at Anacostia on balloons filled with hydrogen and others filled with helium, which, at the time, was disguised under the name of argon. One shot into the hydrogen balloons was sufficient to explode them, while a number of shots into the argon-filled ones produced no effect other than a scorching of the envelope at the point of entrance of the bullet."-Secretary Daniels Nat'l Press Club Speech, 25/2.

The DOUBTFUL FACTORS IN THE PROBLEM OF TRANSATLANTIC Flight.That a flight across the Atlantic Ocean will be made in the immediate future is almost certain. It is, in fact, altogether remarkable that isolated feats of this kind have not been achieved before now. The establishment of anything like a regular aerial transport service over the Atlantic is, however, quite another matter. It would be unsafe to predict how soon, and under what conditions, this will be realized.

The monumental report of the Civil Aerial Transport Committee, recently, published in England, embodies some discordant ideas on this interesting. question. Few persons give more study to the problem of transatlantic Aight than Commander Porte, whose preparations to undertake such a journey in the summer of 1914 were terminated by the outbreak of the war. This authority, as quoted in the report just mentioned, believes that the direct route between Ireland and Newfoundland is at present out of the question, and that for many years to come the only practicable route will be by way of the Azores. Commander Porte also considers Newfoundland an unfavorable terminus for the westward journey, on account of the obstacle opposed to a safe landing by the notorious fogs of that region. He prefers a landing ground on Long Island, thou its distance from San Miguel (Azores) is about 2250 nautical miles, as compared with 1346 miles from San Miguel to Newfoundland.

The elements of uncertainty in transatlantic flying are almost wholly meteorological. The proposed Azores route offers the advantage of the trade winds for the westward journey. Whether, and to what extent, the counter-trades, which blow above the trades and in the opposite direction, could be utilized for the return journey to Europe is still doubtful, because we lack precise information about these winds; particularly as to the level

at which they blow. In higher latitudes westerly winds prevail, but they are much interrupted by cyclonic storms. Here, again, the question arises whether it would be possible to fly high enough to secure comparative immunity from adverse currents

That the coasts of Newfoundland are habitually shrouded in fog seems to be taken for granted in all speculations about Atlantic flight. The British report, however, contains two communications from authoritative sources which emphatically discredit this idea. Sir E. Morris, who has lived and yachted along the Newfoundland coast for years, declares that fog prevails there only with winds from a quarter between northeast and southwest, while the prevailing winds are from west and northwest. He has seen a whole season from April to November pass without rain or fog. He also emphasizes the fact, borne out by a letter from another resident of Newfoundland, that the fogs of that region are generally very shallow. This, we recall, was likewise the experience of the U. S. Coast Guard observers.

The moral of all this seems to be that a meteorological and aerological survey of the North Atlantic Ocean and the adjacent coasts should be undertaken as soon as possible, with special reference to the needs of aeronautics. That air lanes across the Atlantic are destined to become of great economic importance hardly admits of doubt. The study of surface meteorological conditions over the ocean, the corner-stone of which was laid by Maury in the middle of the last century, has yielded results of indispensable value to mariners. Maury depended for his data upon the mariners themselves; but the Maurys of the air should better this plan and anticipate the demands of aerial navigators, by a systematic campaign of scientific expeditions ad hoc. This method would obviate heavy losses in both life and money in the early stages of trans-ocean flight.-Scientific American, 3/1.

AERIAL MAIL IN THE UNITED STATES AND ABROAD.—By Otto Praeger, Second Assistant Postmaster General.—The Aerial Mail Service was inaugurated May 15, 1918, and during the first six months of its existence its operations covered 68,892 miles, at a cost of $75,165.94, including 6 per cent on investment and 3373 per cent for depreciation. In that period it carried between Washington and New York 74527/2 pounds of aeroplane mail. The revenue derived was $60,653.28. The net deficit, not taking into account the 6 per cent interest on investment, was $8,969.08. In addition to the aeroplane mail carried there was dispatched between Washington, Philadelphia, and New York in the six months' period a total of 91,926% pounds of first-class mail, aggregating 3,667,040 letters. This mail was advanced in dispatch from 6 to 12 hours, which many times made up for the small deficit in the operation of this service. This ordinary mail was letter mail from distant states, which was carried in addition to the aeroplane mail. Thus the ordinary mail put on the planes at Washington was usually mail from the South Atlantic Coast states and the Gulf states, distributed to carriers by the Railway Mail Service before reaching Washington, and by reason of aeroplane dispatch was delivered in New York on the same afternoon instead of the following morning.

The Washington-New York route was established not as a typical commercial line, but to solve the problems that had to be met to establish a daily dependable schedule. The flying record made on the New YorkWashington line has never been equaled in the history of aviation, and its operation by civilian flyers of the Post Office Department has far exceeded its operation while under military control, the civilian fliers having a record of but seven forced landings in 100 consecutive flights and only two failures in that time on account of fog or storm conditions. The mail has been carried in blinding rain and hail, on fog-bound days with visibility of not over half a mile, and in the face of gales. Only two winter gales were strong enough to prevent the aeroplanes from com

pleting their journey. On Thursday, January 23, the mail was brought south as far as Silverside, Del., in the face of a 65-mile gale at an altitude of a few thousand feet.

The fastest time of flight carrying the mail from College Park to Belmont Park, N. Y., a distance of 218 miles, was 1 hour and 30 minutes, and the slowest time for a continuous flight was 4 hours and 56 minutes. The average time is 2 hours and 40 minutes. The common experience of the users of aeroplane mail is that a letter posted in the down-town stations in Washington as late as 10.50 a. m., and leaving the aviation field at 11.30 a. m., is usually delivered between 4 and 4.30 in the afternoon, which is in ample time before close of business

Extension of Service.-The greater distance between the points on an aerial mail route the greater is the service rendered to commerce and the greater is the patronage of the line. A mail service leaving New York at 6 in the morning and arriving at Chicago before 3 o'clock in the afternoon, in time to connect with carrier deliveries, will advance the mail between the two cities by 16 hours over any train dispatch that can be made after the departure of the Twentieth Century Limited from New York at 2.45 p. m. The department desires to establish this line immediately and extend it west to the foot of the Rockies during the coming fiscal year, with the view of reaching the seaports of Seattle and San Francisco, if Congress authorizes the appropriation necessary. The air mail time between New York and San Francisco will be less than 40 hours. It is desired that this transcontinental trunk line shall be tapped by lines from Minneapolis, St. Paul, St. Louis, Kansas City and other points, and ultimately by a line from Boston, via Albany, Buffalo and Detroit, to Chicago.

A north and south trunk line from Boston to Atlanta should likewise be established, with an ultimate extension from Boston to Montreal, Canada, and from Atlanta, via Key West, to Habana. Based on the accurate cost accounting kept in the operation of the Washington-New York air mail line, the cost of an east and west trunk line from New York as far west as Omaha and a north and south trunk line from Boston to Atlanta has been carefully estimated at $1,600,000. To this should be added $400,000 for several essential feeders that would connect up Detroit, Minneapolis and St. Paul, St. Louis, Kansas City and other points, and would admit of an extension as far west as Salt Lake City, this extension, however, dependent upon the extent to which the government equipment can be transformed into strong and safe mail-carrying machines.

For this reason it would be very desirable to obtain an appropriation of $2,000,000 for the ensuing fiscal year.-Flying, March, 1919.

THE SIGHTING PROBLEMS OF THE AVIATOR.--One of the greatest difficulties experienced by aerial fighters, when machine guns on airplanes came into general use, was to hit the target aimed at. This may seem, to the uninitiated, like a bald statement of poor marksmanship, but in reality it is not. As a matter of fact, to bring down an enemy machine without specially designed sights is nothing more nor less than pure, unadulterated luck.

For instance, imagine two machines passing each other along parallel lines, 100 yards apart, each traveling 100 miles per hour. You are equipped with a machine gun firing 700 shots a minute- 1 each second-the bullet traveling at the rate of 4,960 feet per second. If you took a dead aim at the enemy machine your first bullet would miss its mark by 18 feet, and the second bullet, coming 1-11 of a second behind the first one, would miss its mark by 45 feet.

To offset this, and to make aerial fighting more of a science, ring sights were devised. These sights consist of two rings, a small one, representing the bull's eye, and a larger one encircling it, representing the line of Aight of the bullet. If aim is taken when the enemy machine is crossing the outer

circle (the hostile aircraft being 100 yards distant and traveling at the rate of 100 miles per hour) the bullet would reach it as it enters the smaller ring, constituting a direct hit.

But this only compensates for the speed of the enemy machine. You still have to make allowance for the speed of your own machine. This is done by means of the Norman Compensating Foresight, a bead sight fitted to a swivel, with a wind-vane swinging on one side, which raises and lowers the bead, and revolves on its axis, according to the pressure of the wind in the slip-stream.

The most wonderful of all sights, however, is the Aldis Optical Sight, used for stationary guns when firing through the blades of the propeller. This sight was invented by the two Aldis Brothers, manufacturers of lenses, who, under subsidies from the British Government, have brought the making of high grade lenses to a higher point than the German's finest workmanship.

The Aldis sight is virtually a telescope which neither magnifies nor diminishes, and which, unlike an ordinary telescope, can be used with the eye several inches from the end of the tube.

SILHOUETTES ILLUSTRATING THE USE OF THE RING BACK-Sight WITH THE

WIND-VANE FORE-Sight. (The former is set for the estimated speed of the adversary, while the

latter automatically compensates for the speed of the plane on which it is mounted. The upper row of silhouettes is for a range of 200 yards; the lower row shows the same objects at 100 yards.)

When looking through this tube at a distant object the effect is exactly as though one were looking through a napkin ring—the object appears the same whether it is seen through the tube or outside it—but, apparently suspended in the air, is a ring sight. The peculiarity is that the ring is seen with its center on the spot at which the tube is pointing, no matter where the eye is placed. If the eye is moved sideways the ring appears to move with it through the telescope, so that the direction in which the tube points is always toward the center of the ring.

The tube, when fixed rigidly to a gun, thus constitutes a sight which offers practically no obstruction to the view, and which shows instantly the spot at which the gun is pointing, without the necessity of alining the eye on a front and back sight. The effect produced on the pilot of seeing an enemy machine flying into this ring suspended in mid-air is quite startling.

One advantage of this sight is that it can be used with both eyes open. One eye sees the object and the circle through the tube, the other eye

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