distributor. A device which may helping to the resonators at the plugs carry only very low voltages is an advantage not to be overlooked. the introduction of this method of ignition, recently placed on the American market, consists of individual Among what may be termed future converters attached to each spark plug. possibilities of automobiling may be These converters are nothing but high- mentioned the Shilowsky gyroscopic frequency Tesla resonators, about 1.5 car, on two wheels like a bicycle, but in. in diameter and one inch long. with a gyroscope device to ensure staA circuit-breaker and distributor are bility. In tests recently made in Lonused, but as low tension is used in the don the car could remain standing for distributor, storage-battery current is an indefinite period, took angles with just as good as that from a magneto, ease, and could be handled in crowdwhile the fact that all the wires lead-ed streets without difficulty. AUTOMOBILES JOSEPH A. ANGLADA cylinder cars even at higher prices than for four-cylinder cars having the same power. In this connection it is interesting to note that one prominent maker having a large output, will build only eight-cylinder cars during 1915 (see Mechanical Engineering, supra.) The Automobile Industry.-Figures | indicating that the public want sixcompiled from trade mediums indicate that the production of gasoline pleasure cars during the year ending Oct. 30, 1914, amounted to 650,000 cars. During the preceding 12 months the production was 571,900 cars. It is estimated that close to 800,000 cars will be produced during the year ending Oct. 30, 1915. During the 1913 period 169 manufacturers were engaged in the production of gasoline pleasure cars, during the 1914 period 161, a decrease of eight, while it is estimated that during the 1915 period there should be about 175. Manufacturers of gasoline commercial cars dropped from 214 in 1913 to 210 in 1914, but a number of new makers have entered this field during the past few months, so that the number has increased to 245 for 1915. Gasoline Pleasure Cars.-The general trend of prices of gasoline pleasure cars is downward; they vary from $5,000, with a limited number above this amount, down to $300 for a diminutive two-passenger car and $175 for a single-passenger child's automobile. The number of automobiles sold for less than $500 has increased from 750 in 1913 to 18,300 in 1914, with a probable increase to 330,000 in 1915 due to the largest maker of machines selling for slightly over $500 having reduced the price to slightly over $400. The number of six-cylinder cars manufactured, which was in 1913 about 12 per cent. of the total number of cars manufactured, increased in 1914 to nearly 13 per cent. of the total. It is estimated that this percentage will be close to 18 for 1915, Cyclecars. This type of car, designed generally to sell for less than $400, promised at the beginning of the year to be an important factor in the industry, but due to defective design and an endeavor to build too cheaply, the public has not purchased many of the cars offered and the manufacturers who have remained in business have turned their attention to producing small cars, light in weight and embracing the general construction of the larger cars. Gasoline Commercial Vehicles.-The older manufacturers have added one or more smaller models to their line of gasoline commercial vehicles, and while some of the manufacturers of larger sizes have ceased manufacturing, new makers have entered the field with vehicles of small capacity. Probably the most important development in this line has been the manufacture of vehicles having a load capacity of 1,000 lb. and selling for about $650. The use of all steel bodies has increased, likewise the use of wormdrive rear axles instead of chain-drive axles for three- and five-ton trucks. Fire Trucks.-The manufacture of motor-propelled fire-fighting apparatus has been steadily advancing. There has been a slight increase in the number of manufacturers of this class of er's standpoint as compared to wood wheels fitted with demountable rims. machines, while the number of manu- | with tires inflated ready for use count facturers of tractors adapted to re- in their disfavor from the manufacturplace horses on existing fire apparatus has increased from two to seven. Electric Pleasure Automobiles.The tendency during the year has been to make electric pleasure vehicles noiseless in operation and more luxurious in interior finish as well as more roomy. There have been some attempts to build electric vehicles which would sell at the popular prices charged for the small gasoline-engine cars, but because of the high cost of a suitable storage battery, these ventures have not been successful. Electric Commercial Automobiles.The manufacturers of this type of vehicle have appreciated the advantages of coöperation to the extent of educating the electric light companies to appreciate that the charging of electric commercial vehicles can be made a profitable part of their business. The result has been an increase in the number of these vehicles sold in fields where their use is more profitable than the use of gasoline vehicles. Steam Pleasure Automobiles. In certain sections of the country, particularly New England, this type remains popular. The perfection of automatic means of controlling the steam boilers used, has simplified their operation and has made their use safer. Steam Commercial Automobiles. The limited number of machines of this type built serves to show that the gasoline and electric commercial vehicles satisfactorily meet most requirements of the uses of commercial automobiles. Design. The use of electric starting motors and electric lights on cars selling for about $750 and over, is almost universal practice. The use of compressed air for starting purposes and of acetylene gas for lighting has been practically abandoned in favor of the electric system. The tendency in body design has been toward "streamline" effects, where the motor hood, dash and body join in easy curves instead of sharp depressions and angles. The use of wire wheels has increased slightly, due to the lighter and more "sporty" appearance given to the vehicles. The greater difficulty of keeping them sightly, and the difficulty of carrying two complete spare wheels Fuels. During the year there have been at least ten carburetors adapted to the use of kerosene placed on the market. In addition there have been at least three so-called kerosene vaporizers, and for a short period it appeared that the use of kerosene as a fuel for automobile engines might be realized. Experiences in the hands of users of these various devices prove that none of those tried were entirely satisfactory, the chief difficulties met with being difficulty in starting, the deposition of an excessive amount of carbon in the engine cylinders and the inability to run the motor at different rates of speed. The incentive to use kerosene as a fuel came from a threatened increase of the price of gasoline, but during the past six months the price of gasoline has decreased to the figures extant about four years ago, viz., 12 to 18 cents per gallon. The quality of the gasoline, that is its ability to vaporize readily, is not as good as that of the gasoline formerly purchased at this price. The increase in the quantity of available gasoline and the lowering in price are due to improvements in the art of refining; the ability of the motor-car engine to use a slightly lower grade of fuel is due to the improvements made in the carburetors. The price of gasoline has been affected also by the use of a fuel known as "motor spirit," produced by some of the large refiners from natural gas (A. Y. B., 1913, p. 591, 600, 663). Abroad, especially in England and Germany, where the price of gasoline averages about twice the American price, the use of mixtures of denatured alcohol and benzol has been popular. Tests made in England of a mixture of one-third benzol and twothirds denatured alcohol have proven entirely satisfactory from the standpoint of power developed by the motor, the running of the motor at various speeds, and the cost of fuel per horse power per hour. The laboratory of the Automobile Club of France has undertaken the experiment of developing an engine to use denatured alcohol as a fuel, the incentive being that denatured alco- | heating the alcohol carburetor. Such hol can be produced in unlimited quantities where the sun shines and the rain falls. The experiments conducted by the U. S. Department of the Interior have shown that it is possible to operate an engine satisfactorily on denatured alcohol provided the compression is increased to about 180 lb. per sq. in. and provision is made for an engine will deliver from 20 to 30 per cent. more power than a gasoline engine of the same dimensions and use but slightly more fuel per horse power per hour. (See "Comparative Fuel Values of Gasoline and Denatured Alcohol, in Internal-Combustion Engines," Department of the Interior, Bull. 43.) AERONAUTICS HOWARD HUNTINGTON long endure, if efforts now being made to bring about an arrangement between Mr. Wright and the industry, mutually beneficial, are of any avail. The future of air craft in the United States depends largely upon its development in the fields of sport and commerce. Aeroplanes.-The development in this branch of aeronautics has been in refinement of detail rather than in any change in type. If there has been any trend from one type to another, it has been in favor of the biplane over the monoplane. Indeed, the tractor biplane has risen to first place in the esteem of military authorities. For long-distance crosscountry flying, this type has proved itself superior to the monoplane, as it will carry a heavier load of fuel with the same span of wing (having two supporting surfaces instead of one), and because it is capable of a greater slowing down in speed without descent, making possible a slower and safer landing speed. General Survey of Progress.-De- | it had not been for the unsettled convelopment in the field of aeronautics dition of the patent situation. This during the last twelve months has condition of affairs, however, will not continued with consistent success. Few radical departures from standard practice are recorded in the design and construction of aeronautical machines. In the uses to which air craft has been put, however, progress has been both startling and spectacular. Achievement has rested almost entirely on the other side of the ocean. The United States, which eleven years ago gave to the world the invention of the successful aeroplane and in 1909 won the primacy of the world in duration and speed, has been lagging behind more and more, until now seven or eight countries are ahead, not merely in the number of machines and pilots but in the holding of records and in the design and construction of the machines. Two reasons are apparent which explain this disparity between our former and present positions in the art and science of aviation. In European countries the military has been very active in the development of the aeroplane. The United States is not a military nation, and our Government has been slow to encourage constructors with orders. As aviation has not yet developed along commercial lines, this military situation has been a controlling factor in bringing about European leadership in the air. The second explanation for tardy progress in America is found in the Wright patent situation. Aviation as a sport has been taken up to a greater extent here than abroad, and it is this phase of development which promised in 1913 to rehabilitate American aviation. There were over 40 interested sportsmen who would have become converts to this new sport in 1914, if The monoplane has always been a tractor machine, but the biplane has only in the last year or two developed into a tractor. By enclosing the power plant, the pilot and passengers in a stream-line fuselage and by reducing the number of struts between the planes, the biplane has been brought to a high state of refinement and its speed is now greater than that of the monoplane of equal power. A neat arrangement in the modern tractor biplane evolved in Great Britain during the year, is the setting of the upper and lower planes at different angles. By placing the upper surface at five degrees angle of incidence to the line | therefore, toward larger and fewer exof flight, and the lower plane at three posed members. degrees, it is found that the machine, when tilted for the getaway, lifts well on both planes, and when in full flight with tail high, the lower plane cuts through the air edgewise with little resistance, and the machine practically becomes a monoplane. By this design great range of speed is gained, the Sopwith machine in England and the Curtiss machine in this country having attained a range of very close to 40 to 90 miles per hour, carrying pilot, passenger, and fuel for four hours. The Sopwith biplane, fitted with pontoons and powered with a 100 h. p. Gnome motor, won the annual competition for the Jacques Schneider Maritime Aviation Trophy at Monaco against a field including several monoplanes equipped with double the pow er. It is this great range of speed which is the most important development of the year in aeroplanes, for, granted that speed of travel is of prime importance, it is also essential to slow down the aeroplane for a safe landing. On any but the smoothest fields a landing at a speed of over 50 miles an hour is highly dangerous, and a machine capable of sustaining itself at a slower speed will have the added advantage of coming to a stop in a much shorter distance after alighting. This range of speed means quicker getaway and more accurate landings, which in turn obviate the old necessity for large and specially prepared aviation fields. The wing curve has passed through further development and it is now practicable to sustain weights upward of ten pounds per square foot of surface without the necessity of extreme speed. The latest wing design has been clearly influenced by the stream-line idea, which is everywhere asserting itself. In fact, the cutting down of head resistance is now conceded to be of the greatest importance in increasing the efficiency of the aeroplane. To this end also the struts and the running gear have undergone some alteration. In the Eiffel Laboratory, in France, it has been found that, with the increase of size, the strength of a strut of stream-line formation increases more rapidly than the head resistance. The tendency is, Stability. In the matter of stability, an interesting development has taken place during the year in this country. The Dunne aeroplane (A. Y. B., 1913, p. 603), invented in Great Britain several years ago but never highly developed, has been taken up and developed along slightly different lines by the Burgess Company in Massachusetts. The result has been gratifying in two ways: inherent stability has been manifestly proved, and efficiency has been maintained. Unlike the results obtained in Europe, stability has been gained without the sacrifice of ease of control in landing, and a speed range has been found which compares favorably with the more standard machines. The pilot of the Burgess-Dunne finds it entirely possible to drive without thought of balance either longitudinal or lateral, and as in an automobile, his only care is to steer his course. This applies even in winds with a velocity of 40 miles per hour. Another means of stabilizing air craft is found in an American invention, the Sperry stabilizer. This is a mechanical device which acts, in the case of an otherwise normal aeroplane, as an automaton correcting any deviation from an even keel by the changing of the angle of incidence in ailerons placed near the wing tips. The controlling factor in this device is a system of gyroscopes which work the ailerons through electrical control. A Curtiss flying boat equipped with this stabilizer was entered in the French competition (Union pour la Stabilitie en Aeroplan) held during the summer near Paris, and won the first prize of $10,000 against a large field of European aspirants. There are many workers in both schools of stability, inherent and mechanical. Inherent stability bids fair to be all sufficient when in full flight, but in flying low for a landing, the rolling of the inherently stable type becomes an element of danger, except in calm weather, and manual control of the balance seems necessary. Hence it would seem probable that a combination of inherent and mechanical stability will be developed in the near future. Hydroaeroplanes.-During 1914 very | adapted than any other type of flying little change has taken place in the craft for sporting purposes. During design of the hydroaeroplane. In con- the summer a dozen of these craft, in struction, however, improvement is the hands of as many amateur sportsevident in the more sturdy construc- men, have proved to be very satisfaction of the pontoons, which are of ne- tory pleasure vehicles. They aggre cessity subject to rough usage even in gated over 250,000 miles of flying smooth water. Further advance in without an injury to pilot or passenthis type of machine is similar to that ger. When used merely as a motor which applies to the aeroplane, viz., boat on the surface of the water, this refinement of detail and increase of type of machine is most interesting to efficiency. It is interesting to note operate. Capable of speeds upward that the development of the hydro- of 60 miles an hour, the pilot of a aeroplane has proceeded along differ- flying boat can maneuver around the ent lines in Europe. There the double highest speed motor boats, and may pontoon or catamaran arrangement turn sharp corners without danger of has been universally adopted, while in a roll over, owing to the slanting balthis country the constructors hold to ancing floats at the wing tips. the single pontoon with balancing short, the flying boat is the most flexifloats at or near the wing tips. ble craft in the handling and the safest flying machine so far developed. The latest flying boats, fitted with enclosed cabin, carrying from two to seven passengers, fitted with luxurious upholstery and marine instruments, present the appearance of highly comfortable and highly developed pleasure craft. In 1915 we may look to this type, in combination with developments in inherent and automatic stability, for the introduction and extended use of the flying machine among amateur sportsmen. Flying Boats.-Like the hydroaeroplane the flying boat is designed to arise from and alight upon the water, but instead of having watertight pontoons beneath the planes, the flying boat carries its passengers in a hull which resembles a high-speed motor boat. This type of air craft is a later development than, and indeed quite distinct from, the hydroaeroplane, each being developed from a different standpoint. The earlier water flier is an aeroplane with floats placed under it; the later type is a boat with wings attached. The developments of the year in this type have been primarily in the line of efficiency in respect to hull design. The earlier flat-bottom hulls had the disadvantage of "spanking" the waves when at high speed, imparting a series of severe jars to the whole structure. The V-type bottom of 1913 was better in that it broke the impact upon landing and upon striking through the waves, but had the very decided disadvantage of throwing a heavy spray high over the lower planes, and under certain conditions, of interfering seriously with the rapidly revolving propeller. The hulls brought out during the summer of 1914 are V'd up from the central keel for a little over half the distance to the edges of the bottom, where the planking is curved slightly down, the effect being to throw the spray downward, which, of course, makes also for efficiency in the lift. The flying boat is more perfectly In Dirigible Balloons. Several types of dirigible balloon have been evolved in Europe, but owing to the military value of these craft, little is known of the more recent progress in their design and construction. Germany leads every other nation in this development. France has held to the nonrigid type of dirigible, Italy and Austria have done much in the development of the semi-rigid balloon, but Germany, with her Zeppelin and Parseval, leads the way in both the rigid and non-rigid class. The tendency in the non-rigid development has been to increase the length of the car carried beneath the balloon, thus bringing about a better distribution of the weight, the cars being of a rigid-frame construction. In Austria and Great Britain the nonrigid balloons have been modified by the construction of a rigid frame at the front end of the envelope, thus permitting higher speed without the deformation of the forward end by the pressure of air at that point. The |