The future of the Liberty motor is a problem that is occupying a great deal of attention at the present time. It is not a power plant that can be used in automobiles or trucks. Its power is far greater than anything now required in such service. The motor might be used for racing motor boats, but it is distinctly an airplane engine built as an emergency measure for war purposes. No doubt a large stock of the motors now on hand will be retained by the government for the development of the air service of the army and navy which will have to be maintained on a large scale as long as the possibilities of war confront us. Airplanes will also be used in rapidly increasing numbers for postal service and no doubt to a considerable extent for pleasure, because the vast army of young men who have learned to navigate the air will not be content to remain on the ground. -Scientific American, 7/12.

SPEED AND HEIGHT RECORDS BY TWO-SEATER MONOPLANE.-The War Department authorizes the following:

Maj. Gen. Wm. L. Kenly has received information from Dayton, Ohio, that the Loening two-seater monoplane in recent tests there developed 145 miles per hour with full military load, including four guns, which is in excess of any record made by a European single-seater combat machine. The Loening plane in these tests also climbed 25,000 feet in remarkable time and carrying two passengers, thereby establishing another new record.

Air service officers here have watched the progress of this new plane in its tests with great interest. This monoplane is American designed and American built. Its construction embodies several new and original ideas. Smaller, of course, than the De Haviland 4, which is a bomber and reconnaissance machine, it weighs only about 2400 pounds loaded for the air, which is practically the weight of a single-seater scout. It is driven by an eight-cylinder, 300-horsepower Hispano-Suiza engine and the whole power plant is a unit construction and may be easily removed from the body of the plane. Several original ideas are also carried out in the understrutting, and the arrangement of the seats is such that the pilot has 50 per cent more vision than in any other combat machine produced before or during the war. The Leoning monoplane carries sufficient fuel for three and one-half hours.

Grover Cleveland Loening, the designer and builder, is an American. He has been an aeronautical engineer in this country for the last eight years, is the author of text-books used in study by American flying cadets, and has been given the degrees of bachelor of science by Columbia University and master of arts and civil engineer by New York University. His address is Loening Aeronautical Corporation, 45 West Eleventh Street, Long Island City, N. Y.—Official Bulletin, 3/12.

A NEW ITALIAN OBSERVATION BALLOON.-The chiefs of the aerostatic section of the Italian army, Major Avoria and Signor Prassove, Director of the Italian Army Aircraft Works, have produced a new type of observation balloon providing much more satisfactory results than the ParsevalSigsfeld kite balloon or the trilobal Cacquot balloon, according to L'Aeronauta. The new type is essentially a spherical aerostat fitted with what are equivalent to stabilizing fins, and acting as a kite. It may be employed in winds of over 55 miles an hour, whereas the Parseval-Sigsfeld type could not be safely used in winds exceeding 12 miles an hour. The new type requires a smaller gas volume for equal load and owing to its smaller dimensions is easily transported and housed, while in flight it represents a smaller target to aircraft fire. A further advantage in the employment of mooring cables of small section follows from its smaller head resistance, while, should the mooring cable snap, the observation balloon may be operated as a free balloon.-Scientific American, 7/12.

SUBSTITUTE FOR GOGGLE GLASS.-It is understood that the Medical Research Board of the Division of Military Aeronautics has found a substi

tute for glass for aviators' goggles. The substance, which is not glass, has been on the market for some time, although it has not hitherto been possible to cast it in the right strength and thickness for goggles. The substance is described as hard and non-inflammable, and is said to ensure practically a non-shattering lens.-Scientific American, 7/12.

NEW AMERICAN BATTLE MONOPLANE.-How fast America is reclaiming the aeronautical supremacy that was hers when the Wrights startled the world with their air expeditions is attested by the latest accomplishment. This is an American two-seater combat monoplane, designed and built by Grover Cleveland Loening, an American, and developed, as quite proper, in the "native habitat" of aero inventors, Ohio. The tests made at Dayton this week developed 145 miles an hour in speed, carrying four machine guns, which exceeds any European record by a machine of this type. The monoplane reached an altitude of 25,000 feet, carrying two passengers, another top mark. The machine weighs 2400 pounds, fully equipped, which is on a par with the single-seat scout planes used in the war. The motor is an eight-cylinder Hispano-Suiza, built in this country. The seating arrangements give the pilot fifty per cent more vision than any plane yet produced. It is much smaller than the de Haviland 4, with which the American fliers made aeronautical history on the west front in France, and its tank capacity is sufficient for three and one-half hours at maximum speed. Mr. Loening is head of an aeronautical corporation in Long Island City, N. Y., bearing his name. He is a bachelor of science, Columbia University; master of arts and civil engineer, New York University, and the author of text-books in use by American flying cadets. His invention is regarded as of great military importance by Major Gen. William L. Kenly, U. S. A., Director of Military Aeronautics.-Army and Navy Journal, 7/12.

CAPRONI'S PROPOSED 18,000-HORSEPOWER AIR CRUISER.-It was announced on November 11, at the annual meeting of the Aero Club of America, that Mr. Gianni Caproni, the famous Italian airplane constructor, is planning to construct an air cruiser of the heavier-than-air type with a number of motors aggregating 18,000 horsepower. The armistice having lifted the ban on the discussion of coming aeronautic developments, the Transatlantic Flight Committee of the Aero Club of America, of which Mr. Henry A. Wise Wood is chairman, made known the fact that there are several airplanes already being designed, each to be equipped with 5000 horsepower. Caproni has one such machine, and it was in connection with the discussion of this type that it became known that Caproni has an 18,000-horsepower air cruiser under consideration, which will be capable of carrying a large number of passengers in non-stop flights across the Atlantic. The famous British constructor, Handley-Page, is also planning to manufacture a 5000-horsepower machine, and similar plans are under consideration in the United States.-Scientific American, 7/12.

THE SEAPLANE.-At first glance, the giant seaplane of our navy appears formidable while resting on the water, and still more so when hauled up on shore where its boat-like body lies fully uncovered to view. In flight it does not seem so large; indeed, it might well be mistaken for the smaller flying boats by the layman, since all aircraft are deceptive while in flight. But viewed close up there can be no mistake about the size of this craft, with its 110-foot span, two Liberty motors developing from 400 to 500 horsepower each and driving propellers 101⁄2 feet in diameter, and a body over 50 feet in length. The fact is that the body, or hull, is nothing short of a 50-foot yacht, but instead of velvet-cushioned berths and other comforts its interior is given over to a tangle of braces, wires, steering and controling devices, instruments, a wireless station, a six-station intercommunicating telephone system, fuel tanks and guns, all of which are the means of com

bating the U-boat and of carrying out long-distance patrols at sea. On the water the seaplane develops a speed up to 50 miles an hour, and the moment it slips off the surface and soars upwards the speed increases to 100 miles an hour.

As in every other heavier-than-air machine, the naval aircraft engineers have had to secure strength in their structure while keeping a strict eye on the weight. Thus the required strength of every piece size consistent with the great strain to which they are subjected. The webs, but 4-inch thick, are but little more than their name implies, sections being cut from the center and ends of each, leaving only a frame suggestive of thin slices of Swiss cheese. At intervals across the uncut portion of the webs are secured small battens, which are less than -inch in thickness. Diagonal braces of piano wire, the tension of which is adjusted by turnbuckles, are stretched between the beams. Every part is carefully varnished as if for display and the whole covered by fabric stretched until it rings like a drum. The

strength is there, to be sure, but the weight is not; so that a 40-foot wing, eight feet in width, which appears to weigh at least a ton, is readily lifted by one man.

This same construction is followed in the entire seaplane. The keel is but little more than a strip of wood, but a perfect system of bracing makes it strong as a steel girder. Multiple-ply veneer measuring less than -inch in thickness is used for planking and hull side covering. Brace wires and light tubular steel struts reinforce the entire structure. Every point not subjected to a direct strain is covered with fabric. Perfect materials and workmanship make the hull a canoe in weight and a torpedo-boat destroyer in size and strength.

There is no haphazard work about the building of one of these boats. Every piece of wood or metal is given an individual part number. Each one is designed for a particular place and the use of jigs and dies makes possible a degree of standardization of wood and metal parts which is as near perfect as can be reached in aircraft production.

The building of the boats is carried on in a series of progressive operations, each group of workmen having its particular part of the work to perform. Each man becomes an expert at his task and speed as well as excellence is attained.

Applying the Lesson of the Automobile Manufacturer.-Starting at the end of the huge shipbuilding hall, a hull is built from the laying of the main members of the skeleton or frame to the completed flying boat. By having a sufficient number of the frames in the different stages of construction, it is possible to send a completed hull out the door at the opposite end of the shop every day. The frames are built upside down up to a certain point, when they are turned right side up and the work continues to the finished hull. The frames are covered with thin veneer, marine glue, fabric and paint in forming the body of the huge seaplanes. While the hulls are being turned out the accompanying wings, tails, cable and other equipment are being produced in like manner so that they can all come together in the assembling plant.

Throughout, the progressive manufacturing methods are applied. It is possible to trace the progress of any given member of the seaplane from the crude to the finished product in the many departments of the grea factory. Quantity production methods have been applied wherever feasible, but it is evident to the visitor that aircraft production calls for a vast amount of hand labor that cannot be replaced by machinery.

Six thousand separate and distinct pieces of wood are used in each seaplane. To hold these in place requires 50,000 wood screws and 46,000 nails, braces and tacks. Of veneer over 600 square feet is used, as well as 4500 square feet of cotton fabric of unusual strength which takes the place of the expensive Irish linen formerly associated with airplanes. The 250 pieces of tubing aggregate 1000 feet in length. To adjust the tension of the 5000 feet of wire and cable over 500 turnbuckles are required. About 1500 each of bolts, nuts and washers are needed to hold in place the 1000 metal strips and fittings which are used in the seaplane. And every piece, which in any respect varies in size or shape from another, has its part number.

Completed, as depicted in the headpiece illustration, one of the navy seaplanes weighs with its crew of five men about 14,000 pounds. It is generally equipped with one Davis non-recoil cannon and four Lewis guns, and has a cruising radius with its two motors and 500 gallons of gasoline of ten hours flight. Primarily its purpose is bombing, and four powerful depth bombs of 250 pounds each are suspended beneath its wings.

The work on the navy seaplane does not stop with the final assembly. There still remains the large task of disassembling its parts and boxing the complete outfit for overseas shipment. This work of packing includes not only the wings, ailerons, stabilizers, rudder, motors and propellers, but the hull as well. Three crates hold the seaplane being shipped, the principal and largest one, of course, being the one containing the hull. Next in size is the box holding the main panels, engine panel (the short, central section immediately over the motors), ailerons, and all accompanying struts, staywires and control cables. The third and smallest crate contains the tail section, consisting of the vertical and horizontal stabilizers, elevators, rudder and the braces, stays and cables required for their installation. The packing is done by a department that does nothing else. Seventy-five men are kept busy packing the huge seaplanes.

Changes in the present seaplane are being constantly evolved by the Engineering Experimental Department of the Naval Aircraft Factory. Altogether, they have first built three types of boats necessitating some 12,000 separate drawings and almost as many tests of material. One type of boat was designed, developed and built in 117 days. Another type was built and launched on schedule time, III days:

All changes are originally placed in the hands of the Experimental Section to develop, design and place on a manufacturing basis. Even after

the boat is completed, it is their problem further to perfect the separate parts. In the case of one design shipped to Europe, Admiral Simms, U. S. N., cabled 13 or 14 improvements. Seventy-five per cent of these had already been worked out by the Experimental Section and were then in production. The remaining were designed, built and installed within four days from receipt of the recommendations.

All in all, the Naval Aircraft Factory is a permanent institution to which` we can turn both now and in the future for our naval aircraft needs.Scientific American, 14/12.

MERCHANT MARINE

MERCHANT TONNAGE SUNK.-World's Total During War Was 15,053786 Gross Tons.-The world's total losses of merchant tonnage from the beginning of the war to the end of October, 1918, by enemy action and marine risk was 15,053,786 gross tons, according to official announcement issued to-night.

During the same period vessels totaling 10,849,527 tons were constructed and enemy tonnage totaling 2,392,675 was captured, making a net loss of tonnage during the war of 1,811,584.

British merchant tonnage losses were 9,031,828 gross tons from the beginning of the war to October 31, 1918. New construction in the United Kingdom in the same period was 4,342,296; purchases abroad were 530,000 tons, and enemy tonnage captured was 16,520. The net loss was 3,443,012 tons. Washington Evening Star, 6/12.

TURBINE-PROPELLED VERSUS MOTOR-DRIVEN VESSELS.-In a review of shipbuilding developments in the Scandinavian countries, London Engineering observes that turbine-propelled vessels are also attracting increased attention, and their advocates think they will be the most serious competitors of motor-driven vessels. In this respect also Norway is well to the fore, and a new type, the so-called Brodin type, was launched the other day from the Frederikstad shipyard, Norway, it being christened the Arcturus. The dimensions are 300 feet length, 47 feet breadth, depth 23 feet, and draft 19 feet, 9 inches, 4600 tons, deadweight. The special feature is connected with the location of the ship propelling machinery, the boilers, bunkers, and the turbo-electric driving seats-two turbo-generators of 600 i. h. p., each, generating three-phase current-are placed amidships, while the motors and gearing are placed aft, the current transmission being by cables. This arrangement ensures a saving in space, resulting in an increased cargo capacity of about 100 tons, in addition to which the consumption of coal is claimed to be smaller, by about 200 tons, than in a vessel propelled by ordinary steam engines. This means a 200-ton deadweight increase in loading capacity. At the trial trip a speed of eleven knots was reached. The consumption of coal was guaranteed at 0.45 kg. best East Coast coal per indicated horsepower per hour, and this condition was fully complied with. The Frederikstad yard has orders in hand for 25 vessels of this type.-Nautical Gazette, 30/11.

MISCELLANEOUS NOTES

THE SECRET OF THE "BABY" TANK.-It will always remain a troublesome feature of military writing that the most interesting things cannot be described in full until they have ceased to be timely. A month past, when battles were still raging on the fields of France, a drawing of the interior details of a small French tank would have been most opportune, since hundreds of these weapons were being used by the French and the Americans. But military exigency precluded the presentation of such material for the very reason that it was then too opportune and too interesting-particularly to the enemy. So it remains for us to publish details