Aeronautics

Volume 16 - No. 7 - 1915 June

Table of Contents PDF Document


The American Magazine of Aeronautics was the first commercial magazine in the United States of America about national and international aviation. There were reports on patents and flight contests. The journal was published from July 1907 to July 1915. All pages from the years 1907 to 1915 are available with photos and illustrations as full text, for free.

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VOL. XVI. No. 7

JUNE 15, 1915

15 Cents

EROfMCTIC

ilkik

160 H.P. Model

The output of this model is sold for some weeks to come. Those desiring motors of this type should communicate with the factory at Hammondsport for the necessary arrangements for future deliveries.

All the important American records are held by the Cur-tiss Motor.

Modern factory methods and large facilities have developed Curtiss ^Motors to the highest degree of ■ .efficiency.

Simplicity of design and construction permit overhauling or re! pairing by any good mechanic, no

special knowledge being required.

Light in weight, yet not so light that durability and strength are sacrificed. The factor of safety is large in Curtiss Motors.

69

Curtiss Motor Co.

HAMMONDSPORT NEW YORK

m m

m

m

2476�14159248612

984554

AERONAUTICS' DATA SHEET No. 19

"AIRHOLE" AT LANDING.

The velocity of the air at the surface of the earth is not the same as at some elevation from it, and the air may be perfectly still at the ground level while at a comparatively slight height there may be a wind of some 10 m. (,32 ft.) per sec. This is due to the protection afforded the lowest layers of air by the unevenness of the earth surface.

If a flyer runs against a wind of 10 m. per sec, with an absolute velocity of 25 m. per sec., his relative velocity is 15 in. per sec., and when he suddenly enters a stratum of still air his velocity remains only 15 m. per sec. which is not enough for planing: as a result he hits the ground with a thud, having struck an airhole. In landing, it is always a safe thing to select a fully open place where there is nothing to keep the iciud out. The height of fall through an airhole is directly proportional to the velocity of the aircraft. Let G be the weight of the apparatus: v the velocity of the aircraft in still air; Vi the wind velocity, h the height of fall. Further, let -'i = 10. When the craft is in air having Vi = 10, its kinetic energy is

_ C v>

2g

where g = 9.81. When the craft passes into the air having ti = 0, it loses some of its kinetic energy, which then becomes G

A, = - (r-i-0'

The difference between the values of A\ and Ai indicates the kinetic energy A required to bring the aircraft back to the speed that would allow it to float in the lower air stratum. In this case Vi = v — 10. which gives after substitution: 10.C

A = - (v — 5)

3

What is wanted, however, is to establish the relation between v and h. When a craft of weight G falls through h, a kinetic energy A=Gh is liberated, and therefore G/i may be substituted for A in the preceding equation, which finally gives 10

h= — t> - 5).

g

But q is approximately equal to 10. and therefore

h = v — 5

may be accepted as being approximately correct This equation shows that the height of fall through an airhole increases with the speed of the aircraft, and that it is independent of the weight of the aircraft (the latter because G does not figure in the equation for h). Table 1 gives the height of fall through an airhole due to the craft corning from air moving against it at 10 m. (say 32 ft.) per sec. into still air, as functions of the sneed of the airship,— (Das "Luftloch" bci der Landung. K. Heinkel. Der Motorwagan, Vol. 16, No. 4, p. 91, Feb. 10, 1913. V/2 pp.. 1 fig. />/. A.)

(Table on Data Sheet No. 20)

AERONAUTICS' DATA SHEET No. 18

COEFFICIENT OF RESISTANCE OF SYMMETRICAL BODIES ACCORDING TO M. EIFFEL.

When a critical speed exists for a body here listed then the coefficient of resistance is given for velocities above the critical speed. When the coefficient is variable otherwise, then it is given for speeds around (0 mi. p. h. These coefficients should be sufficiently accurate between speeds of 30 and 70 mi. p. h. The metric coefficient Km is in kilos and metres per second—the Ke in pounds and miles per hour.

Km Ke

Disc (30 cm.) (coefficient increases with size

with a limit of K = .08)...................07 .0028

Sphere (for all sizes tested)................. .01 .0004

Cup. hemispherical, concave toward wind*.....10 .004

Cup. convex toward wind....................02 .0008

Cylinder, short. 1) = II......................023 .00092

Cylinder, long, less than......................02 .0008

Wire, all sizes ( at 22 m/s = .06 ].............065 .0026

Vibrating wires, same as above...............065 .0026

Inclined wires at 30° Km = .012 at 45° Km

= .028 .................................... — ■-

Cables, all sizes ..............................07 .0028

Strut, streamline, 74 x 25 mm................ .007 .00028

(*Cup, at 16 m/s speed, Km = .09 increasing to .10 at 26 m/s.)

—Compiled by M. P>. Sellers.

SPEEDS IN MILES PER HOUR REDUCED TO FEET AND METERS PER SECOND.

5 miles

per hour

_

7'/i ft. per

sec. =

2.235

mete

IO "

 

=

i4Vi " "

"

4.470

"

15 •'

"

=

2itf " "

" =

6.705

20 "

" "

=

2g'/3 " ■•

" =

8.941

11

25 "

   

36^ " "

 

I I.I76

11

30 "

<t (I

=

44 " "

: _

'3-4II

"

35 "

"

 

5'#" "

" =

15.646

11

40 "

" "

=

ssy} " "

" =

17.882

"

45 "

1* II

=

66 " "

"

20.117

 

50 "

II II

=

73/3 " "

" =

22.352

"

55 "

II (1

=

807-3 " "

"

24.587

t 1

60 "

II II

 

S8 " "

' =

26.822

it

70 "

II II

»

102^ " "

It __

31-293

 

80 "

   

117J/3" "

"

35-763

 

90 "

II II

 

132 " "

 

40.234

 

100 "

• I •■

 

146? j •' "

" -

44,704

it

Published semi-monthly in the best interests of Aeronautics by AERONAUTICS PRESS INC. 250 West 54th St.. New York

Telephone. Circle 2289 Cable. Aeronautics. New V;rk

ERNEST L. JONES Editor

M. B. SELLERS Technical Editor HARRY SCHULTZ Model Editor

FRANK CASH Ass't Editor

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OUR TUTORS IN THE ART OF FLYING

By JOHN J. MONTGOMERY, Professor of Santa Clara College

[Editor's Note.—Professor Montgomery wrote the following article for Aeronautics after his gliding experiments were stopped at the time of the San Francises earthquake, but it has never before i.een published. It will be remembered, from Aeron'avtics for October. 190S. to January, 1909. that he built gliders with warping wings with which glides were made from thousands of feet in the air when freed from hot-air balloons, in 1904 and 1905. Professor Montgomery was killed in making some gliding experiments himself, October 31, 1911, having renewed his work in anticipation of building a power machine, with the aid of Victor Lougheed and James K. Plew, of Chicago. The full story of his life work was printed in Aeronautics for November, 1911, written by himself. Professor Montgomery claimed for himself the invention of wing warping.]

The airy waste around us impresses one as an unexplored and untried region, rilled with enchanting ideals and possibilities, and we contemplate with the keenest interest and cherished hope the performances of the feathered creatures that follow their lives of labor or pleasure in its free expanse. And though we may have become accustomed to the sight from unlimited opportunities of observation, we can never resist the temptation of watching the maneuvers of a large bird as it moves along its unseen path, without apparent effort, as if it were a creature superior to the gross things of earth. Each performance seems novel and gives some little light that leads us nearer to an understanding of the mystery and the solution of the problem. And as we observe the varied feats of the same or different birds under diverse conditions, we always find something to correct our first crude ideas .and expand the limits of our conceptions.

In the mountain regions, where 1 performed my first experiments in gliding flight, 1 have watched for hours at a time the easy, graceful movements of buzzards, in the hopes of catching their secret and imitating them. While I remained hidden in the bushes they would pass within a few feet of me, sometimes just above, then in front and again below me, gliding to and fro, tilting and

moving to one side and then the other; sometimes sinking and then rising. Vet all these movements were produced by changes in the adjustment of the wings or body too slight to be detected. P>ut in my crude attempts at imitation, under identical conditions, my gliding machine would make only short flights and gradually descend. And it not un-frequently happened, while I was floundering along in my machine, these birds would glide by time and again, or circle around, and. ascending in bounds, reach elevations of hundreds of feet in a few moments.

While the soaring of these birds is usually easy and graceful, it is not always so. Once during a fierce gale I noticed a buzzard, within twenty feet of me, fighting its way against the storm. There was no attempt at flight by flopping the wings; these were nearly closed, and the bird had somewhat the appearance of diving. It kept up a slight rocking movement, sometimes it would descend and advance and then ascend and recede: but it never varied its position more than a few feet, and though there were no movements in tin body, the act seemed to be one of an intense struggle. As the surrounding country was an open plain, there was no chance for protection in the lee of some hill, and there was nothing but a fair and square contest between wind and bird. Failing to make any advance it opened its wings just a little and shot upward with startling velocity, about three hundred feet, and receded about a hundred: and then continued its journey by successively diving and rising.

Movements somewhat comparable to these are exhibited by a species of hawk that sails at great height, watching for its prey, the California quail. When it sees its victim it dives from its high position with such terrific speed as to produce a loud whistling sound, and when near the ground, with its wings nearly closed, shoots horizontally, with the swiftness and directness of an arrow, through the flock of startled and swiftly flying quail. If it succeeds in seizing one. it flies away with its prey: but if not. it rapidly ascends on motionless wings to a great height, to repeat the attack.

We are accustomed to hold the eagle

as an ideal, and it is certainly worthy of all we think of it. and more. It alone impresses one that it is master of its domain. Its every movement conveys this impression; and they are all so complete and perfect that it teaches us how to glide or soar by demonstrating every change in adjustment with the corresponding movement through the air.

My favorite place for observing these* birds was a secluded spot on the side of a precipitous mountain, the home of nearly a dozen splendid specimens. As they would glide almost within reach— above, below or before me—every change in adjustment could be seen.

The turning or twisting of the wings or tail, the contracting and expanding of the wings and their backward or forward movements, with the corresponding evolutions, were all easily seen.

Sometimes they would engage in play or combat, and then their powers of flight, agility and mastery over the air were fully manifest.

And their control over every phase of flight, from darting down hundreds of feet below to rising hundreds above, to soar where'er they wished, was so perfect and easy that one irresistably felt that the mastery over the air must be within easy reach.

In the high mountains regions, especially those skirting the desert, we occasionally find the California vulture, a giant among birds, whose flight impresses one with its power and majesty. From some mountain tops they may be seen slowly circling and rising out of the deep canon below. And as they approach and glide by or circle with slow majestic movements over the awful rocky abyss, one feels an inexpressible thrill, and as he watches them gracefully rise thousands of feet above him and glide away to some distant mountain range, be longs for the time when he may securely rest on his wings and fearlessly ascend to these dizzy heights.

One of the plainest, most matter-of-fact and business-like exhibitions of soaring I have seen was that of a flock of pelicans that spent a few months rusticating on San Diego Bay. They were line specimens, with large golden pouches, pure white bodies and wings which were tipped with black. Those

that I killed weighed twelve pounds and their wings were nine feet from tip to tip. There was just a hundred in the Hock. They would fish for a while in the morning, and then go for a sailing excursion over the surrounding country. After reaching the height of about a thousand feet they would commence to soar in great circles, keeping in line, one after the other. Viewed from a distance, their column presented a series of waves, the indi\iduals successively descending and ascending.

Their wings were arched down and extended to their fullest extent. <ui watching these immense birds soaring on motionless wings, two striking points impressed themselves: First, there were twelve hundred pounds sustained and moving along without apparent effort; and, second, this not on a single surface, but several in tandem.

As a sharp contrast to the usually easy and graceful movements of soaring one may see, during ocean voyages along the coast, the wild flight of a large bird much resembling the albatross. It has very long and narrow-wings, which arch down, but from a distant side view look like two clumsy sticks. It never flaps its wings except in starting, and when once under headway it glides at terrific speed and. in the face of a strong wind, rapidly passes the vessel. Sometimes it circles around the vessel time and again. At times it skims along the surface of the water, at others it soars aloft, gliding away to great distances, then returning, but at all times tearing along as if it were mad.

Of the various exhibitions of soaring, that of a certain field hawk seems to bring the subject nearest to us. It usually Hies very near the ground, but sometimes starts to soar. In doing this it will fly upward about twenty feet, and then, spreading" its wings, will successively glide down and up, circling as it does so. The difference between its descending and ascending movements is peculiar.

In the descent, the horizontal motion is rapid, and the following ascent is quick and abrupt, almost suggestive of a jump. The rapidity with which it rises is very surprising and the transformation can hardly be realized. We see it flying here and there, barely above the ground, then it simply soars up hundreds of feet and glides away. The operation is so simple and easy, so near at hand and so often repeated that it is almost tantalizing.

In making mention of these few instances of soaring, I have presented them as 1 have found them, sometimes there was wind, sometimes none.

When one has on endless occasions seen birds rise thousands of feet, when there was not a breath of wind apparent anywhere, and when smoke in the neighborhood would rise vertically hundreds of feet; or when he has seen eagles easily soar aloft on the lee side of a mountain in windy weather; or when scattering thistle-down in a wind over a level plain, he finds it hardly rises 20 feet in a thousand, he is not bothered much by the prevailing, upward-trend-of-the-wind theories.

However, most of the instances 1 have

mentioned were selected because of the absence of wind.

On two occasions it was my good fortune to witness phenomena that brought the subject of soaring very close to us.

The first was at the head of San Diego Hay, where I noticed an object high in the air moving" slowly along. The sky was dotted with clouds and the prevailing wind was about 4 miles per hour.

The object was just below the clouds and moving with them, but seemed to be going faster. On viewing it through a strong field glass, I found it to be a large piece of light brown paper more or less crumpled and having a slight rocking motion. I started to follow it. hoping it would come to earth, but as it manifested no such tendency, but rather disappeared in the clouds, I abandoned the attempt. The second was at this college two years ago when my experi-l ments rather enthused the small boys and they took to making small airships! and parachutes and dropping them from the high buildings. They made parachutes out of light tissue paper, with a small figure fastened to the lower ends of the strings. All these come to earth in the regular manner excepting one, and this started on a cruise. When my attention was called to it. it was about a hundred feet high and slowly drifting' south. The movement of the air was southerly, but so gentle that it turned the anemometer on the observatory only occasionally, so that the velocity could hardly lie determined. Vet the little thing kept ascending and receding, taking a path about 45 per cent with the horizon, and in about twenty minutes was lost to view.

THE WILL TO FLY IN LITERATURE

By Prosper Buranelli

The aeroplane, as an object for the thinker, holds a unique place, in that it is a materialization of the most persistent dream which has haunted the human species; and is, as well, the most thorough and excellent embodiment of any dream.

At the dawn of history the will to fly-was venerable with age—yet no less vigorous with youth, nor has its vigor ever dimmed. Never so wide nor so ardent a contagion as the quest for the philosopher's stone, nor the moto pcrpctua, to mention none other: it has been more constant, more unobtrusive, too (you will say because it was more possible), and it is in every respect the type of aspiration which, shared by all men, and •deemed futile by most of them, has been followed by a few with desperate tenacity. And, now, it has been fulfilled— and well fulfilled. For the aeroplane, -even though it never be what is known to the generality of people as useful, is still the finest realization of a want well nigh essential to the human soul that lias ever been achieved.

Xot merely to fly has been the long-drawn cry, but to fly like a bird. The -very soul of the will to fly must be

sought in man's envy of the bird, of the mobility, the freedom, the power of the bird, and no mode of aerial locomotion could satisfy the "great heart of mankind" nearly as fully as the winged aeroplane.

The ancient longing for wings is dead. It is fulfilled. Nevermore shall a man envy the soaring eagle, nor shall a poet bemoan that man can only crawl. It is victory, and yet sadness must come to the meditative mind for the aspiration of the ages that is gone. Then it is well for one to betake himself to literature, the psychic records of our species, and commune with the will to fly as given expression by these tongues of human aspiration, the great creative artists of literature, and especially those of poetry. Geothe is the finest in this respect, I think. In Faust, to my mind, are the greatest expressions of our species' longing to fly which are to be found in all the reaches of art. The song of the spirits whom Mephisto conjures to lull Faust to oblivion, and. above all, Faust's great appostrophe to the setting sun. Act II, Scene 3, are transcendent expositions of the will to flv.

Here are presented several odd lines from the latter, translation of James Stuart Blackie:

The Sun slants down, the day hath lived his date,

But on he hies to tend another sphere. () that no wing upon my wish may wait

To follow still and still in his career! Upborne on evening's quenchless beams to greet

The noiseless world illumined at my

*fr ¥ -fc

The heavens above me. under me the sea.

A lovely dream! meanwhile the god is gone.

Alas! the soul in winged fancy free. Seeks for a corporal wing, and findeth none.

Yet in each breast 'tis deeply graven. Upward and onward still to pant,

When over us lost in the blue of heaven. Her quavering song the lark doth chant; * * *

Harry Payne Whitney is planning to become an aviator. He has ordered one I of the latest types of Burgess-Dunne 1 aeroplanes.

TECHNICAL TALKS—By M. B. Sellers

EIFFEL'S "NOUVELLES RECHERCHES"

Aerofoils.—M. Eiffel found that when the speed of the air current was varied. Kx and Ky for some wings also varied; the variation with increasing speed being always such as to improve the wing aerodynamically and to increase the lift ratio.

A number of wings were examined for lift, drift and center of pressure, about which I shall say more at another time.

Constantin Profile.—It was found that the modification of the entering edge of an aerofoil, by making it concave above, as shown in Fig. 1, improved both lift and lift ratio of some wings, especially thick ones, to an appreciable extent; others were improved only slightly or not at all.

TLLIXE PONTOOM

Howard Wright Profile.—This wing resembles two or more wings joined together, the under side forming a continuous curve. (See Fig. 1.) This showed fairlv good lift and efficiency: Kx

at 6° Ky = .044 and - = .08. The

Ky

center of pressure varies only 2'~< of the width between 5° and 15° inclination.

Entering Edge.—An entering edge with the convexity below (see Fig. 1, B) was found superior to one with convexity above (A, Fig. 1), up to an inclination of 3° in the wing tested.

Aspect Ratio.—Beyond an aspect ratio of 6 there is little improvement; for small curvature the aspect ratio may be less: for a camber of 1/30 it may well be 5.

Ol'TLiNE of Wing.—A trapezoid with the long base to the rear is better than when turned the other way, and better than a rectangle.

Tandem, Canard.—For a given spacing, between the forward and rear wings, the canard improves in lift and efficiency by decreasing the difference in inclination between the wings; for a given inclination-difference increased spacing improves the machine. An inclination-difference of 2° seems the best. Raising or lowering the rear plane has little effect.

(Continued)

Ordin ary Monoplane. — Spacing is of less importance than for the canard. The disposition of the resultants at various incidents is more favorable to stability than in case of the canard.

Tandem, Equal Surfaces.—The loss of lift due to interference is greater than in case of the two previous dispositions. Increased declination and spacing improve stability. The biplane is more efficient than the tandem except below 3° inclination.

( Jffsetting ( Staggering).—Offsetting top plane forward helps the lift; at 5°, Ky is increased from .05 to .06; but Kx is increased in about the same proportion, so there is no gain in efficiency. The increase in lift is obviously an advantage.

Aeroplane Models.—M. Eiffel examined a large number of models, about which 1 hope to say more at another

Kx

time. Here are given the minimum-

Ky

for some of them : that would be the minimum amount of thrust necessary to carry one pound (or any unit of

weight) : Bleriot = 0.2 at 10' ; Do-

rand 0.21 at 8° : Alorane-Saulnier 0.17 at 9.6°: Louis Paris mono. 0.12; Tatin "torpedo" 0.13; Letellier Bruneau 0.106; Bristol 0.16: Farman 0.23; Breguet biplane 0.14. The monoplanes require 5 to 6 h.p. per 100 kg., while the biplanes require 4 to 5 h.p.: this is due to the lighter loading of the biplanes. Allowing 2 h.p. for climbing and 70' i efficiency for propellers, we require about 11 h.p. for nionos, and 10 h.p. for biplanes, per 100 kg., or about 5 h.p. per 100 lbs. for monos, and 4^ for biplanes.

Wheels.—Five kinds of wheels were examined. The coefficient of resistance varied from .044 to .065 for the different wheels. Covering the spokes in the usual way (disc wheels), reduced the resistance 50'v. The four Farman wheels at 25 metres per sec. would offer a resistance of 7.6 kilograms uncovered, or 3.7 kg. covered.

Pontoons.—Three models of pontoons were tried: Fabre. Tellier and Breguet. The Fabre (see Fig. 1) was aerodynamically the best; the full sized pontoon weighs 105 kilos., and at 62 mi. per hour the lift would be 58.5 kilos, and the drift 9.55 kilos. The weight not supported and the resistance to advance would be only slightly greater than if a four-wheel chassis were substituted for the pontoon.

Fuselage. — Two Deperdussin and three Farman fuselages were tried. The Deps. gave the least resistance. These were of the "monocoque" type, one with the motor partly hooded (above) : the other with motor completely enclosed except for an annular hole to permit entrance of air for cooling. Without pro-

pellers these two had resistance respectively equal to an area of (1.178 and 0.150 square metres.

Propellers.—M. Eiffel examined 26 model propellers, about which I expect to say more at another time. It was found that when the relation of Y to XI) (Y = \elocity of air current in tunnel. X = revolutions and D diameter of propeller) was such as to make the efficiency maximum, then there was an acceleration of the air current approaching the screw of ll'r and behind it of V

2Y'<. If--diminished below this,

XD

then the acceleration before and behind the screw increased. It was found that two 2-hladed screws clamped at right angles so as to act as a 4-bladed screw, were nearly as efficient as both acting independently. When clamped at 105° thev gave slightly better results than at 90c.

CURTISS PLANT RUSHED

"Tony" Jannus is now associated with the Curtiss Aeroplanes & Motors. Ltd., in Toronto, Can., in the construction and operation of. various machines which they are building for various governments. It is impossible to give any details as to their construction, horsepower or requirements. To this point the various governments have especially asked the manufacturers to pay strict attention.

The largest training school, both land and water, which has ever existed on this continent is in operation. There are now thirty-eight students enrolled to date, all of whom have been passed and accepted by the British Admiralty or the British Army through their representatives at Ottawa. There is a waiting list of approximately six or seven hundred.

J. A. D. McCurdy is managing director of the Curtiss Aeroplanes & Motors, Ltd.

SIGNAL CORPS HAS FINE PLANT

Mr. Benjamin Foss, of the B. F. Stur-tevant Co., recently returned from the Pacific Coast and states that at San Diego, the V. S. Army Signal Corps has developed an excellent and efficient plant for aeronautical training purposes. He also states that Captain Cowan, who is in charge of the station, and his squad are to be congratulated upon the excellent results which they have achieved, the appropriations for aeronautical purposes being very small. He has under him at the present time thirty officers and as many more enlisted men. fourteen military machines being used.

The power required for the shop and for lighting purposes in anil around the camp is obtained from a Sturtevant gasoline generating set operating twelve to fourteen hours a day with unusual success.

THE CURTISS FLYING BOAT PATENT

The patent just issued to Glenn H. Curtiss (U. S. 1.142.754. June 8, 1915; original application filed September 6, 1912. Serial No. 718,840. Divided and this application filed June 4, 1913. Serial No. 771,b46) (see also patent No. 1.085,575. January 27, 1914) seems to cover for this country all hydroaeroplanes and flying boats, i. e.. combinations of air supporting surfaces with a central float-

A complete history of the hydroaeroplane art was published in Aeronautics, 'January. 1913.

The drawings illustrate the description in the patent, and as readers are familiar with the parts, there is no need to go into the details of this.

The operation of the form of the invention shown in the drawings is as follows: When the machine is at rest on

ing body portion. This patent does not cover balancing floats at the extremities of the main plane.

The Patent Office files give the date of conception as December, 1908; disclosure in Januarv, 1909, and reduction to practice in April. 1909.

After unsuccessful attempts, in January. 1909, with twin canoe-shaped pontoons fitted to the "June Hug," the third aeroplane built by the Aerial Experiment Association, delays occurred which prevented further trials of note until January 26, 1911, when actual flights were made by Mr. Curtiss at San Diego (see Aeronautics for March, 1911, and January, 1914) with a system of two floats arranged tandem, one taking the place of the rear wheels of the triangular running gear and the smaller one replacing the forward wheel. Next a single long boat was tried (see Aeronautics for above dates) on February 1, 1911, and subsequently. Then the experiment was made of Hying to a battleship, hoisting the hydroaeroplane on board and returning to the start. (See Aeronautics for April, 1911. A triplane was also Mown with a central float about this time.

It will be remembered that Curtiss flew with a land machine fitted with means for keeping the machine afloat should it fall in the water, at Governors Island. October, 1909, and from Albany to New York, May, 1910. It was not possihle with these latter machines, however, to fly from the water.

the water it is floated by both the forward and rear buoyant portions so that the tail portion increases the longitudinal stability of the machine on the water. When the machine is moving slowly through the water the bow rises and the tail sinks below its normal displacement, the elevated and upwardly inclined bottom of the tail permitting the tail to he more readily depressed with the tendency of the boat to rock rearwardly as it speeds up. As the boat increases in speed it commences to plane upward out of the water at a greater angle of inclination, and when it attains sufficient speed to bring it well up out of the water, due to the forwardly projecting part of the boat beyond the center of gravity and the proximity of the step to the center of gravity, the boat is adapted to rock forward upon the forward hydroplaning surface and travel on the water supported from the water upon said surface with the tail of the boat well elevated. When the boat is thus planing on said hydroplane surface, the bead resistance is greatly decreased, due to the decreased angle of inclination of the hydroplane surface to the water, the elevation of the tail portion and the decreased angle of incidence of the air planes so that the boat rapidly gains in speed to rise in the air, and, by means of the longitudinal aerial balancing planes, may be readily rocked rearwardly about the step 5 to a flying angle to rise from the water. Even if

the bottom surface of the tail of the boat should not be substantially out of the water at this time, the height of the bottom surface of the tail above the rear extremity of the hydroplaning surface will permit this rocking movement without the rear of the tail engaging the water to an undesirable displacement; and if it should engage the water, its flat surface will prevent undue suction of the tail in the water such as would hold the machine in that position.

ABSTRACT OF CLAIMS

In a hydro-aero machine, the combination of one or more relatively narrow main air plane supporting surfaces extending out transversely of the machine in lifting relation thereto; a relatively long, narrow, rigid floating means or central body boat with overhanging bow-floating substantially the entire machine on the water and comprising—a ( 1 ) forward buoyant portion having a fairly broad and deep hydroplane surface (as compared with the tail portion to render the.boat seaworthy, give lateral stability and accommodate an effective hydroplane surface) commencing at a point well in advance of the forward edge of said main planes and of the center of gravity of the machine, extending downwardly and rearwardly along the overhanging- bow at a relatively sharp angle to provide a gliding bottom giving substantial resistance to the boat's diving, thence rearwardly more horizontally in the form of an effective hydroplane surface of such length as to permit the machine to plane upon said surface on the water in gaining speed to raise the tail portion from its normal displacement to facilitate breaking from the water, terminating in a (2) rearwardly facing step in the vicinity of a vertical line through the center of gravity of the machine intermediate the forward and rear edges of the main supporting surface, said step terminating the lowermost hydroplane surface of the machine; and (3) a buoyant rear portion extending from a point in the vicinity of the said center of gravity vertical line to a point well to the rear of said line and aft the rear edge of said main air plane surface, the water-submerged side portions of the tail tapering rearwardly to form a tail portion decidedly lighter and of decidedly less displacement per unit of length when the machine is at rest on the water than the forward broad, deep buoyant portion, said rear portion having a bottom surface commencing at the rear of the step and higher than the bottom of said forward hydroplaning surface, inclined upwardly and rearwardly as a reverse hydroplaning surface beneath the tail, free of head resistant surfaces extending down to said hydroplane surface as would prevent the rocking of the machine about the step, whereby the machine may rock vertically about the step, forward onto said hydroplaning surface and plane on the water at speed with its

light tail portion raised above its normal displacement, with the air plane surface at an angle of incidence less than when the machine is at rest, in order to readily break from the water, when the boat is planing at speed, the machine when at rest being supported on both bottom surfaces of above buoyant portions to give longitudinal stability, the bow being free from aerial balancing and aerial propelling means:—longitudinal aerial stabilizing means located at the rear of the machine, means for driving the machine at such speed as to raise the tail portion and cause the entire machine to be lifted from the water, including an engine mounted above the central boat intermediate the forward and rear edges of the main supporting surface; an air propeller direct-connected and located substantially at the rear of the main plane: a cockpit and an upper deck portion extending from the nose of the boat upwardly and rearwardly to give the bow depth and protect the aviator from wind and spray, in the forward buoyant portion ; an aviator's seat, control mechanism for the lateral and longitudinal aerial stabilizing and for the propelling and steering means located forward of the aerial propeller and in the cockpit, whereby said stabilizing and propelling means are protected and a forward view of the aviator unobstructed by the same; a vertical aerial rudder on the stern of the tail portion and a stationary vertical tin in longitudinal alinement with the forward end of same : horizontal stationary air planes in each side of said h.n and elevators at the rear of said horizontal planes and in alinement therewith :—the 28 claims of the patent comprising combinations of all these separate elements severally and individually; the abstract above given, covering all qualifying combinations cannot be taken literally as representing the text of all claims, as it is a composite statement.

CURTISS OPENS BUFFALO SCHOOL

The Curtiss Aeroplane Co. is establishing a training school in Buffalo. Mr. Curtiss has donated a Curtiss flying boat to the Naval Militia of New York State and agrees to train one aviator and me-I chanic. This is primarily the reason for the locating of the school in Buffalo and any additional naval flyers desired will be taken here along with civilian students.

The site selected is an ideal one. adjacent to the Buffalo Yacht Club and fronting on Lake Erie. A standard Curtiss flying boat and also a large model "K" flying boat will be used. The hangar has been erected.

B. H. Kendrick's flying boat has just been launched at Hammondsport and will be taken immediately to Atlantic City. Air. Kendrick's home, where it will be used for passenger carrying throughout the coming season.

SECURITY LEAGUE ISSUES CALL FOR PUBLIC SUPPORT

Better coast defenses, a definite military- and naval policy, a budget system for appropriating money instead of the present "Pork Barrel" method in Congress, an effective mobile regular army, better go\eminent support for the Na-

in the districts of opposition. Steps have already been taken for branches in nearly 200 prominent cities.

All those interested in the work of the league are invited to send their names and any contributions to the National Security League, 31 Pine street. New York City. Membership is $1.00 yearly; contribulting membership, $5.00 yearly; life membership. $25.00.

f fs

4xi

tional Guard, and the creation of an organized army and navy reserve are among the platform planks upon which the National Security League is sending out an appeal for immediate public support.

Among the names which appear in the membership of this league for national defense are: Joseph H. Choate, former Ambassador to England, honorary president; Alton B. Parker, honorary vice-president: S. Stanwood Menken, president : former Secretary of War Henry L. Stimson, chairman of the army committee; J. Bernard Walker, chairman of ihe navy committee; Benjamin F. Tracy, former Secretary of the Navy: Colonel William C. Church, editor of The Army and Xazy Journal.

In the call for support, the league points out that "until a satisfactory plan for disarmament has been worked out and agreed upon by the nations of the world, the United States must be adequately prepared to defend itself against invasion, and also that a military equipment sufficient for this purpose can be bad without recourse to militarism." The league was formed, continues the appeal, "as a preparation not for war but against war."

It is the present plan of the league to make national defense an issue at the coming session of Congress. With this program in view, branches are being organized all over the country, especially

MAYO AEROPLANE MAKES A SUCCESSFUL FLIGHT

The Mayo military tractor biplane, which was constructed in New Haven at the factory of the Mayo Radiator Company, has had its first flight, and from every standpoint it was a great success. Steve MacGordon, the pilot of international reputation, was at the wheel and he circled the Yale bowl and the surrounding territory for a period of 14 minutes.

WICHITA WANTS BALLOON RACE

Wichita is hoping to get the national balloon race. Such was tbe announcement by Walter P. limes, chairman, and Edward F. Mclntyre. manager, of the Wichita Fair.

Mr. Mclntyre asserts the city is located a greater distance from a body of water than any other place from which a flight could be made. The general direction of the wind during October, it is said, would send the balloons northeast, which allows them a distance of 1.000 miles without fear of dropping in a lake.

If tests to be made in Chicago prove satisfactory, natural gas can be used to till the hags, according to Mr. Mclntyre. He was assured, he said, that if natural gas cannot be used, hydrogen will be made.

U. S. MILITARY AVIATION

Lieuts. Kilner, Fitzgerald and Sutton finished the junior military aviator tests Saturday, May 15. In order to complete the straightaway 90-mile crosscountry flights, Lieut. Sutton, in Xo. 32, and Lieut. Kilner, in No. 27, flew from here to Long Beach. Cal.. each making the trip in about two hours. They were considerably held back by strong head winds. The same afternoon Lieut. Fitzgerald, in No. 32, and Lieut. Kilner, in Xo. 27, left Long Beach at 2.10 p. in., reaching their destination neck and neck, in an hour and forty-six minutes. Both machines glided in over the hangars and landed abreast.

The scheme of organization for the First Aero Squadron is now almost complete. Capt. 11. 1). Foulois, the squadron commander, is responsible for the details of the organization. He has been engaged on this difficult undertaking for the past eighteen months and has produced a very thorough and finished system. Capt. Foulois is the first military aviator in the world and has had a breadth of experience in both heavier and lighter than air craft, which makes him eminently qualified for this task. At present there are eleven officers in the squadron, and it is expected that there will be eight flying machines with the organization by July 1. These machines are of the Curtiss J.X. 2 type, and are now at the Curtiss factory awaiting the results of the tests of one. It is contemplated that fourteen motor trucks and two machine shop trucks, all four-wheel drive, and six motor cycles will constitute the transportation section, which is not yet complete in vehicles. The squadron is now organized for purposes of instruction and training into the following twelve sections: Heodquarters, supply, engineer, transportation and eight flying sections.

Tests of No. 41, the first of the eight new Curtiss tractors ordered for the First Aero Squadron, are progressing.

The automatic electric stabilizer, invented by A. J. Macy. and first demonstrated in Hopkinsville. Ky., Xovember, 1913, in a Day tractor piloted by De-Lloyd Thompson, has just had an exhaustive test at the Signal Corps Aviation School. The mechanism was installed in Signal Corps aeroplane Xo. 31, a Martin military tractor biplane. The machine was piloted on different occasions by Capt. Dodd, Lieuts, Taliaferro, Milling and Jones, Mr. Raymond Y. Morris, chief pilot, Curtiss California Company, and Mr. Oscar A. Brindley. civilian instructor in flying. After careful tests, these officers reported that the device kept the machine balanced, afforded automatically the correct hank for turns, made when the aviator used only his rudder, and that it was of such simple, rugged construction as ordinarily to preclude getting out of order. They further reported that the principle of the device is sound and good. Mr. Brindley stated his belief that a stabilizer will be of great aid to the operator in crosscountry flying, since it adds greatly to

the element of safety, to the ease of control, and reduction of fatigue on a long flight.

During the month of April 549 flights were made at the school, by twenty-one aviators, carrying ninety-eight passengers, for a duration of 141 hours and 14 minutes, and an approximate distance of 8,500 miles. One minor accident occurred at Brownsville, Texas, with slight breakage, and one machine was demolished at San Diego, Cal., without any injury to the pilot.

A board of officers is now engaged on a uniform for military aviators. At present the outfit consists of watch, aneroid, compass, helmet, gauntlet, leather coat, goggles and service uniform. The latest types of aircraft are provided with an elaborate instrument equipment, eliminating the necessity of carrying watch, aneroid and other bulky instruments strapped to the wrist and leg. Greater convenience and comfort are sought for the airmen, as the introduction of refinements has demonstrated their value in increased flying efficiency.—Army and Xary Journal.

NAVAL AERONAUTICS

We have fourteen aeroplanes at Pen-sacola. We have fonrteen navy air pilots (expert aviators), and we have eight student naval aviators, and a class of ten more are to be ordered on the first day of July.

ARMY CONTRACTS FOR SHEDS

Plans and specifications for the aeroplane sheds to be erected at the Army Post at Fort Sam Houston, to house the aeroplanes of the proposed aviation school, were opened at the national capital in the office of the chief signal officer, June 20. The two sheds each will house five planes and will cost in the neighborhood of $20 000. Corrugated iron will he used in the construction.

WARRING NATIONS

DROP MONOPLANES

For some time France has discontinued all orders for monoplanes, says a cable dispatch. The type was abandoned by Germany early in the war, and since then England has followed the example, so far as orders for additional aeroplanes are concerned. The monoplanes owned by the contending nations will he used less and less, and, according to present plans, no more will be ordered.

AVIATOR DESTROYS ZEPPELIN-ZEPFELINS RAID ENGLAND

Though Zeppelins have been seen over England and about the suburbs of London at various times, and bombs have been dropped, little damage has been done until the raids of May 31st and

June 6th. It seems most likely that the bomb dropping device which Germany | has been manufacturing has at last been put into use. In these two raids the casualties amounted to 24 non-combatants, with many wounded and fires started. The censor is keeping secret the names of the towns visited. The British viewed the havoc wrought "rather phlegmatically, as necessary and expected incidents of war. There was no panic and little excitement." But when French aviators dropped bombs on Karlsruhe "the pleasant little German capital went wild with consternation, the inhabitants ran into the streets half-clad, shouting and screaming. It was a terrible awakening for them to the realities of war."

The Evening Sun says :

"There is nothing unexpected about Germany's outburst of rage at the bombardment of Karlsruhe by aeroplane. What though it comes hot-foot upon the Zeppelin attack on London and is followed within twenty-four hours by the raid on the northeast coast of England, it stands out in the Teutonic mind as 'a nefarious and senseless art. . . .' They were startled out of the serene confidence in which all civilian Germany seems to have been nursed by the leaders of Kaiserdom—that feeling that nothing was too bad for England because nothing bad ever could or would happen to Germany.

"The Karlsruhe incident is lamentable. The entire system of air raiding is an abomination. Like submarine commerce destroying, it is a barbarous application of modern instrumentalities of war. But, of course, it is absurd to condemn the French for adopting by way of retaliation the German's own method, of which I they and their allies have been repeatedly I the victims since the very first weeks of 1 the war."

The first verified incident of an aviator destroying a dirigible was concerning R. A. J. Warneford, a Canadian sublieutenant in the Royal Xavy, who, on June 7th, attacked the Zeppelin, evidently returning from a trip to England, with incendiary bombs, causing its fall to the ground, wrecked. On May ISth three German airships were reported destroyed by gun fixe.

It is reported the British government is now building a number of large aeroplanes similar to the Sikorsky, capable of carrying five men and five times as much ammunition _as the standard machine. This is the line prophesied by Mr. Goldmerstein in a recent issue of Aeronautics.

NEW CORPORATIONS

The Bounds Aeroplane Company, Ma-dill, Okla.; capital stock, $3,500. Incorporators, Overton Bounds, I. E. McMillan and W. H. Baldwin, Madill.

The data sheets are great dope! I hope you will keep them up.—R. S. B., New York.

That data-sheet idea is a fine thing. Keep it up.—C. B., Minneapolis.

OF AMERICA J9 West 39th Street. New York

OFFICIAL BULLETIN

A gootl step was taken by the Aeronautical Society of America at its last meeting, when resolutions were adopted for the establishment of the Burridge Foundation as the result of a bequest to the society by the late Lee S. Burridge, its past president, who died May 4th last.

The purposes of the Burridge Foundation are to print and publish the transactions of the society and thus to give to the public the very valuable technical data comprised in the papers which are read before the society after they have been submitted to and discussed by its Technical Board, and reviewed by its engineering body known as the Aeronautical Engineers' Society. A further and highly important feature of the published transactions will comprise digests of all current data and accounts of improvements in relation to aircraft submitted from time to time to the society.

The value of this latter feature of the society's work cannot be overestimated, because it provides a publicity ontlet for the advanced ideas of aeronautical investigators, after careful consideration by competent boards and the elimination of matter devoid of merit.

The publication in periodical form of current available data demonstrating methods of development in the art and science of aeronautics is bound to prove of immense benefit to the industry in pointing the way to improved design and construction, and by creating contemporaneous records of otherwise obscure knowledge regarding individual investigation with its resulting bearing upon the art.

That its publication may be as complete and comprenhensive as it is possible to make them, the Aeronautical Society of America invites the co-operation of all aeronautical investigators, patentees." designers and builders to submit to it the novel points and facts, theory or practice which they are willing to make public for the general good of the industry, with the assurance of the society that the author in each instance will be given full credit for accepted data.

The importance of this work is incalculable, especially for the reason that the few manufacturers of aeroplanes in

this country are fully occupied with war orders for Europe, running their plants to full capacity in turning out their existing product, and cannot, therefore, be expected to devote much attention to costly, time-taking experimental work; wherefore the general art must depend for advancement upon the enterprise of new comers in the field, who may be expected to avail themselves of tbe latest knowledge extant in the natural order of competitive undertaking.

There are thousands of men all over the country working out plans and ideas for improved means of flight, and to America, which blazed the way to success through the works of such men as Langley. Chanute and the Wright brothers, should also belong tbe glory of developing the art of flying to its inevitable future status of being generally accepted most safe and practical method of transportation.

Memhers desiring to read papers before the Society for publication under the Burridge Foundation are requested to communicate with Rudolph R. Grant, Chairman of the Technical Board, with whom all arrangements may be made for the discussion and preliminaries.

Also, all persons having presumably original matters of aeronautical interest which they are willing to have digested and recorded in the society's printed transactions may submit this data to the secretary, whether it be in the form of patents, blue prints or written description. The Technical Board will then consider each subject as presented and prepare digests of all approved material for publication.

The Society invites, and sincerely trusts it will receive the hearty cooperation of all its members in the effort to make its published transactions, as far as possible, a complete record of contemporaneous progress in the art and science of aeronautics.

Henceforth, in view of the labors of the Technical Board the general meetings will occur only on alternate Tnesdays, the Tuesday evenings in the other weeks being devoted to the Technical Board meetings exclusively. This arrangement will prevail throughout the summer months. Therefore, the next general meeting will be on Tuesday, the 22nd of June.

Harry M. Jones thrilled thousands by his remarkable flights over Dorchester Bay on Memorial Day during the trial tests of his new tractor biplane. Traveling at an estimated speed of 65 miles per hour, at an altitude of a thousand feet, and carrying a passenger, he remained in the air for periods of fifteen minutes at a time, putting his machine

through all manner of manoeuvres.

He has selected a six-cylinder Sturte-vant motor for his power plant, and states that the wonderful success of his machine is due to a great extent to the splendid performance of the engine, which develops over 80 h.p.

A. C. PENN'S NAVAL STATION

The tremendous movement of national defense which is sweeping the country is meeting with big support from the citizenry as well as the governmental departments.

The Xavy having designated League Island as the Pennsylvania aeroplane station, the Aero Club of Pennsylvania intends to equip a real unit of national defense and is now arranging to erect a suitable hangar and in other ways pre-part this station.

Conscious of the value of this governmental concession and thoroughly alive to its increased responsibilities, the Aero Club of Pennsylvania has inaugurated a State-wide campaign, designed to extend its activities and stimulate interest in aeronautics throughout its geographical field of operation.

A stated meeting of the Aero Club of Pennsylvania was held in the Bellevue-Stratford. Friday evening. June 18th; also a meeting of the Board of Directors.

Plans for the erection of a hangar at League Island and the purchase of a military aeroplane was presented at the meeting.

PHILADELPHIA AERO CLUB

The Philadelphia Aero Club. Percy Pierce, president: Alan McMurray, secretary, has built up a live organization of thirty-odd members. In the three years' existence of the club five gliders have been built, shed. etc. One made some fifty flights towed by an automobile. This was described in Fly for November. 1913. Tiie club now has a tractor biplane in which tbe members are learning to fly at $10 a lesson, which keeps the machine in repair. While the machine has but a 30-h.p. Gray Eagle motor, air-cooled, the aeroplane serves its purpose.

An article in the July Scribner on "The Aeroplane in Warfare," by Charles L. Freeston, has all the interest of romance, but even- detail is fact based upon months of observation and special study. It gives the most complete information about the part aeroplanes are playing in the present war. There are stories of the exploits of daring aviators.

"The war has tanght us. it has been shown beyond doubt, that, to a large extent, an aviator may be said to bear a charmed life even when over the enemy's fire. Time and time again machines have descended with their planes honeycombed with bullets, and it has been shown that to bring an airman down by gun-fire or ride-fire it is necessary either to kill or wound the man himself or to damage an integral part of the machine to a degree that makes it uncontrollable. RiHe-fi.re has proved ineffective, save by sheer lack, but anti-aircraft guns are a more serious matter."

The aeroplane has brought entirely new problems into war, and the rules that were devised at The Hague Conference have been broken repeatedly. Just what the legal questions are that

are supposed to govern the new warfare is discussed clearly in an article in the July Scribner on "Aerial Warfare and International Law." The author. A. de Lapradelle. is Professor of International Law in the ITniversity of Paris. He has been lecturing" in America.

Guardian is asked for one young aviator and another aviator shot himself recently.

Rear-Admiral Bradley A. Fiske, at the Xaval Academy Alumni dinner, June 3, said:

"An attack by one of the great naval Powers is the only kind we need consider. What would be the character of the attacking force?

"Clearly the attacking force would be as great as the attacking force could spare in order to insure its success and minimize its losses. This means that the attacking force would include battle cruisers, dreadnoughts, predreadnoughts. scouts, cruisers, destroyers, submarines, mine depot ships, mine layers, mine

sweepers, airships and aeroplanes, ali fully manned, and all strategically directed by a general staff.

"What have we with which to oppose this force? A small number of dreadnoughts, predreadnoughts and destroyers than the enemy would bring; no battle cruisers, no effective scouts, one airship recently contracted for, only three good aeroplanes not yet ready, an embryonic aeronautical service, two mine depot ships, one mine layer and twelve mine sweepers: also about forty-five submarines of all kinds and ages, distributed over the Atlantic and Pacific coasts, Panama, Hawaii and the Philippines, none of which has ever attempted the feats like those so effectively performed in foreign navies now; and an inadequate merchant marine from which to get auxiliaries. To man even this insufficient material we have an enlisted force insufficient even for that in time of peace and no trained reserve; and no general staff or similar agency to direct the whole."

President Wilson says: "We are too proud to fight." Whv buy aeroplanes at all?

COMMUNICATIONS

To the Editor of Aeronautics:

Now that the time is Hearing for the advertised transcontinental aeroplane race*, the writer ventures to submit some ideas as to how the most efficient and safest aeruplonc should be made. as. aside from luck and the aviator's skill, the efficiency and safety of the machine will doubtless be the determining fact or s in the race. The objects should therefore be to secure the greatest speed and litt per horse power, to cope with upward, downward, rearward and lateral air currents, land at a slow-speed, rise in a short distance, etc.

the most efficient planes.

In order to secure the greatest lift in proportion to drift from the planes, 1 would divide a given amount of surface into very narrow planes and back-step (completely back-stagger i these planes instead of superposing them or staggering in the usual way. Even a superposed multiplane has been found <by Horatio Phillips) to be much more efficient than the same amount of surface (at the same angle) in monoplane or biplane form, on account of the very high aspect-ratio, and by hack-staggering entirely we prevent any plane from throwing air down onto the top side of the one below, and thus depressing it directly and also indirectly by annulling partly the lift-giving air rarefaction normally existing there; for the suction (except very close) on the one side of a plane or propeller (revolving plane) is negligible as compared with the push given the air on the other side, as is proved by holding one's hand alternately behind and in front of a revolving propeller or electric fan (evidently on account of the air coming in slowly from all directions as a result of the suction); while experiments with models (hy Tcherschersky) have proven that each plane of a completely back-staggered biphane has very nearly monoplane efficiency, instead of simply the upper one having such lift and the lower one having only two-thirds as much, as is the case with a superposed biplane according to Eiffel's experiments; while the head resistance of the upper plane is only one-fifth more than the lower. II ence each plane < except the uppermost ) of a multiplane would have one-half more lift (at the same angle) when back-stepped than when superposed, and as a superposed multiplane (say, with 3 or 6-inch wide planes placed their depth apart or more, the spacing preferably increasing from bottom to top) would probably give at lea>l one-third more lift (for the same angle an 1 amount

of surface) then when in monoplane form, the total lift would therefore be nearly doubled by changing from monoplane to back-staggered multiplane form; while with these very narrow planes the center of lift (erroneously called "center of pressure") could vary at most but an inch or less ordinarily. The back-stepped multiplane, unlike the superposed, would have govd gliding ability—solely for lack of which, in fact, the latter was at first abandoned. Lateral currents could but little affect these narrow-planes, and another advantage would be easily

and quickly variable angle of incidence, thus regulating lifting power and speed at will, permitting slowing for landing, quick rising, high altitude, etc. For this purpose, either the Venetian blind arrangement (only front pivoted) or pivoting the center of a stiff frame of the narrow planes could be used. Also, by curving or sloping the planes slightly downward towara each lateral end and providing upperside vertical or even dihedral sides there, the end losses

from the under side of the planes and the annulling of the air rarefaction on the top side near the ends are both prevented, giving still greater efficiency a method, by the way, applicable to all planes. A very light and narrow "soaring" strip hinged air-tightly to the trailing edge of the planes and allowed a little play between two stops would also, automatically, conserve the rarefaction near the rear of the top s'de, hy preventing the air from curling up over the trailing edge so easily. Air deflectors at '.ha top side of the entering edge, concave or

REAR. Euwrtcy

straight (the former patented recently), may also he used to increase the upper side air rarefaction and hence the lift, as ex|>eriments prove that they more than compensate for their head resistance. (See July. 1913, Aeronautics.) In a multiplane these air deflectors are doubly advantageous, because the upward trend is given to the air just before it strikes the plane next above.

{Continued on Pa.^e 10S)

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AERONAUTICS

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AERONAUTICS' DATA SHEET

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"air-holes" and ailerons. For coping with upward and downward currents {''air-holes") these quickly variable planes would also be superior, especially if the parts on the opposite sides of the central part be made oppositely variable like ailerons, to be used when the latter are insufficient to restore lateral halance; a large and a small balancing lever being arranged side by side so that both may be grasped in the hand at once when so desired. The ailerons would likewise be made of back-stepped multiplanes, but would preferably be normally zero-angle, so as to turn equally as much upward on one side as downward on the other, thus making the head re sistances equal, so that no use of the steering means would be necessary in conjunction, and hence there would be no violation of the orig-

inal Wright patent; while the balancing is accomplished with smaller (and hence more efficient) angles of incidence, and with half the head resistance caused by the Farman system of ailerons (increasing only the low-side angle and decreasing the high-side angle to streamline), and much less resistance than even that of the German (simply producing a negative angle on the high side) or the Wright system.

downwardly turning sections.

Another means of coping with dow n ward currents is to divide the main planes into sections about a foot or two wide (laterally) and hinge them at or near their entering edge (or else at one lateral edge or diagonally between), so that they will automatically and instantly turn downward when a downward current

conies, letting it pass through instead of depressing or capsizing the machine; while these sections \\ill as quickly resume their normal position (up against the under side of the framework) when the pressure from the front or under side again hecomes normal-—greater than that from the rear or top side. (This arrangement is also to be used in connection with hovering cr vertically rising helicopters, the means for accomplishing which I will explain in my next article.)

two elevators for safety.

As to elevators, for safety when upward or downward currents are encountered, there should be both front and rear, interconnected ones composed likewise of back-stepped multiplanes (preferably front pivoted in an immovable frame).

principles of propeller efficiency.

In regard to propellers, ii is easily proven that greater efficiency is secured by slower speeds of propeller and greater areas of undisturbed air covered (the area of propeller circles heing in proportion to the squares of their diameters); also, that the greater the propeller speed (at any point on it) the smaller should be the pitch, while the greater the forward speed of the machine (relative to the air) and (to a small extent) the greater the blade width, the steeper should be the pitch of the propeller -—other things being equal, in each case. Also, it is easily demonstrated that end losses may be prevented with propellers (as with planes) by curving or hending the blad? somewhat backward (in its plane of revolution) from its ends toward its center, so that the air will tend toward there instead of the ends, especially the outer end (notwithstanding this is counteracted in a non-advancing propeller by the rarefaction-side centripetal in flow at the tips), and -that, by inclining the tips slightly forward (axially), making tbe slipstream flare, a large area of undisturbed air is acted on by the propeller tips during forward motion, and hence enough greater thrust secured to more than compensate for the small loss resulting from the slight angle of the thrust near the tips (as with the celebrated Oaruda propeller of Europe). The blade width should increase exactly as the distance from center. All these points would argue for variable-pitch propellers (if sufficiently more advantageous and if practicable), together with larger diameters (or greater number of propellers) and not too great speed, besides depressed blade centers and forwardly inclined blade tips, gradually increasing- in width from center. Hence the two oppositely turning, 8 or 9-foof. 12-inch wide, steep-pitch propellers of the Wright machine, revolving only about 500 r. p. in., give great efficiency; but I would substitute four propellers (above and below and one either side of center) of the same diameter and pitch, but only half the width, as they could be revolved at the same speed with the same power (by not crossing the chain and by arranging tbem as closely together as possible), and by thus acting on over twice as much area of undisturbed air they woidd give considerably greater thrust— theoretically at least 25 per cent. more.

two extra engines and propellers.

Then beyond the two lateral propellers let us arrange two more, similar in size and each directly connected to a quarter-size engine revolving in the opposite direction from the other, together with a toggle-jointed, slip-jointed, bevel-geared shaft connecting the two propellers, so that only temporary differences in tbe power of the two engines would be transferred from one to tbe other.

These engines would be sufficient to propel the machine in case of the larger engine failing partly or even entirely. All the propellers would preferahly be pushers instead of tractors.

reliable steering means.

These outer propellers would be variable angle or even reversible, so as to be used (he-sides as a brake for stopping quickly after landing) in steering more accurately and reliably than vertical rudders or even than lateral resistance surfaces; but 1 would also provide these for engine stoppage emergencies, placing a tall and narrow vertical rudder in both front and rear to cope with lateral currents striking one at a time.

Uncertainty in steering is also obviated by the singly-acting lateral resistance surfaces (preferably vanes on vertical axes), which have

CURTISS FACILITIES

I This is the main factory of the Curtiss Aeroplane Co. at Buffalo where aeroplanes of tractor and pusher type for land and water are built under ideal conditions. The Curtiss Company is the largest and best equipped aeroplane manufacturing plant in the world.

Information on Request

The Curtiss Aeroplane Co.I

Buffalo, New York

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Military~,Tractors Flying Boats Aeroplanes

WIRE

We make an extra high grade plated finish wire for aviators' use.

FOR FURTHER INFORMATION ADDRESS

John A. Roebling's Sons Co.

TRENTON, N. J.

Safest and Most Practical A few of its patented iu. s. and

foreign! features:—Inherent bra-

THE PARAPLANF bilitv. Dual Motors. Controls and 1 1 * r i-»r»J"»r i_mi t. Propeik.rs which can be worked

independent of each other. Propellers and Control so arranged that

machine will tiy just as readily with a single Propeller, Greater Lifting

Power. Changeable Angle nf Incidence.

Especially Designed for Governmental and Private Use

Literature on reyttest

PAR1SANO AERIAL NAVIGATION CO. OF AMERICA, INC.

220 West 42nd Street New York City

BOOKS

I

Send for new and complete catalogue

AERONAUTICS, 250 West 54th Street, NEWiYORK

JUST OUT-

Page 110

aeronauticsI

r

AERONAUTICS' DATA SHEET

No. 23

1

HORSEPOWER FORMULAE.

Four-Stroke Cycle Engines. Authority Formula

A. L. A. II. and Royal Auto Club

D2N 2.5

Brit. Inst, of Auto. En. 0.45 (D-j-L) (D—1.18)

D=LRN

E. P. Roberts.

D = Diam. of cylinder in inches. L= Length of stroke in inches. R:=Rev. per min. of crankshaft. N —Numher of cylinders.

18.000

= H.P.

H.P-= H.P.

Derivation of the A. L. A. M. Horsepower Formula.

The indicated horsepower of a single-cylinder fourcycle engine is equal to one-quarter times the mean effective pressure P, acting throughout the working stroke, times the area of the piston A, in square inches, times the piston speed S divided by 33,000, thus:

PA.S

i. ii. p. = yA-

33,000

Multiplying this by the numher of cylinders N gives the I. H. P. for an engine of the given numher of cylinders, and further multiplying by the mechanical efficiency of the engine E gives the brake horsepower. Therefore the complete equation for I!. II. P, reads: P A S N E

B. H. P. = -

33,000X-J

The A. L. A. M. assumed that all motor car engines will deliver or should deliver their rated power at a piston speed of 1,000 feet per minute; that the mean effective pressure in such engine cyliuders will average 90 pounds per square Inch, and that the mechanical efficiency will average 75 per cent.

Substituting these values in the above E. H. P. equation, and substituting for A its equivalent, 7854 D", the equation reads:

90y.7S54 d2X 1.000 X NiV-75

33,000 X-f

and combining the numerical values it reduces tor B. II. P. = -

or, in round numbers, with a

2.4S9 denominator 2.5.

also been patented by the Wrights; and these in connection with both front and rear rudders would give a quite reliable and efficient steering system.

the high efficiency possible.

By embodying all or nearly all of these efficiency means for planes, propellers and controls into one machine, probably at least two or three times the efficiency of the present aeroplanes could be secured; for it should be borne in mind that they only lift 15 to 40 pounds per horse power, while birds lift 80 to 400. (A successful aviette might even be thus made, if both foot and hand power were used with a single extremely narrow, large diameter propeller and only a vertical rudder for con-

trol.l (>ne other device (hat might well be added would be an automatic balancer, such as the Sperry or Wright, but made instantly sus-pendable, however; this relieving the aviator when tired, or preventing him becoming so, thus enabling longer flights in the race. For automatic stability this multiplane might be built in the form of the Dunne Y-shaped aeroplane.

engine efficiency and reliability.

In regard to the engine, 1 would use a patented device for supplying water vapor to the mixture, thus preventing carbonizing, and would insist on several small extra exhaust ports like a two-cycle engine's, besides two oppositely-opening, reciprocating cam-operated, well-oiled

sliding exhaust valves in the head, with a large 1 oblong port, thus securing rapid, unobstructed and nearly complete exhaust. Also 1 would prefer two self-cleaning spark plugs in each cylinder near the intake (not the exhaust), a silver radiator (if engine is water-cooled), water-heated carbureter and air intake. It should be not over four to six-cylinder (to avoid excessive piston ring length and friction), i long stroke, well balanced, with light yet strong reciprocating parts (preferably steel), ball bear- < ings (the central bearing extra strong) and a single spiral pistol ring to a cylinder. But 1 believe a complete-exhaust, two-cycle engine (with light extra piston in head) will be the , engine of the future.

The writer has not patented any of the devices herein described, and anyone is privileged to use such of them as have not been patented by others.

ELMER G. STILL. Livermore, Cal., .May 24, 1915.

cAERO MART

HANGARS FOR EXPERIMENTAL WORK

UNDER THE AUSPICES OF THE AERONAUTICAL SOCIETY OF AMERICA, AT OAKWOOD HEIGHTS, S. 1„ 35 MINUTES FROM SOUTH FERRY, IS A SPLENDID FLYING FIELD WITH HANGARS AT LOW RENTAL. SUITABLE FOR WORK OF DEVELOPMENT, EXHIBITION AND PASSENGER FLIGHTS. AERONAUTICAL AERODROME, INC.,

317 BROADWAY, NEW YORK, TEL. 1287 WORTH.

WANT TO BUY an 80-h.p. Gnome or an SO or 90-h.p. Curtiss. Address John Weaver, c/o Aeronautics.

FOR SALE—Detroit motor, 30 h.p.. Bosch magneto, special Kingston carburetor, special mountings adaptable to monoplane. Lised one hour, guaranteed better than new. $100.00 cash. H, c/o Aeronautics.

4-CYL1NDER 50-h.p. Roberts with propeller hub and Bosch magneto, $450.00. thoroughly overhauled and guaranteed. Address R, c/o Aeronautics. 2t

6-CYLINDER 80-h.p. Maximotor in fine condition. Complete with Mea magneto and propeller hub, $525.00, taken in trade on a new Roberts, Address R, c/o Aeronautics. 2t

FOR SALE—NEW $2,750 FRONTIER 8-CYL1NDER 80-H.P. AEROPLANE MOTOR, GUARANTEED PERFECT. SACRIFICE, $650. COOKE, 127 WEST 64TH STREET. NEW YORK. 2t

FOR SALE—At the right price, one Baldwin machine with 50-h.p. Gnome. Good as new. J. W., care Aeronautics.

WANTED —Mechanic for Curtiss machine. J. W., care Aeronautics

AERONAUTICS' DATA SHEET No. 21

AERONAUTICS' DATA SHEET No. 20

"AIRHOLE" AT LANDING

Continued from Data Sheet *Vo. 1'J

 

v in miles

 

v in ft.

   

t In km

per [iiin.

c in in

per ecc.

A in m

h In ft.

60

31

14

46

9

29.5

75

47

21

09

16

62.6

100

02

28

92

23

75.5

125

73

35

115

30

98

150

03

42

133

37

122

AERIAL BOMBS AND PROJECTILES

The accompanying chart has been arranged by Wilbur R. Kimball to represent graphically approximate data on falling bombs and projectiles. These values will lie modified by variations in the density of the atmosphere.

The vertical scales of fall in feet may be read for all three curves. The upper horizontal scale may be read for C and the lower one for A and 1!.

The space traversed for any second of time is twice the time (it)minus 1 times 16.08, represented by the curve A on the chart.

The total distance fallen in any number of seconds is graphically shown by the curve U. and is the time in seconds

squared times 16.08, or-

The velocity at the end of fall is gt, i. e., number of seconds times 32.16.

The velocity in feet per second acquired during fall is 8.02 times the square root of the space traversed.

If the projectile has an initial velocity of. e. g., 6-10 ft. per second (on C). approximately that of the projectile fired by a Zeppelin, the corresponding distance shown by the chart which it would have to fall to attain this velocity is 6,400 ft.; and the time required, 20 seconds.

To calculate the time of fall with this intial velocity, add the distances and subtract the corresponding times. For a projection of 6.000 ft., e. g.. add 6.400, making 12.400. requiring 27'4 seconds, less 20 = 7^4 seconds approximately. From curve A the space traversed in the 30th second is 944 ft.

(See Diagram on Data Sheet No. 21)

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Speed range 40-80 miles per hour.

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COMPANY, Marblehead, Mass.

THE BURGESS

Sole licensees of the American-Dunne Patents

mm

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For sport, exhibition or military use, over land or water now embody the improvements that have been suggested by the experiments quietly conducted during the past ten years.

THE WRIGHT FLYING SCHOOL

Located at Dayton opens May 1st, for the season of 1915. Tuition $250. No other charges of any kind. Enroll now. Booklet on request.

The Wright Company

DAYTON. OHIO New York Ollice: II Pin. St.

The 8-Cylinder 140 Horse Power

(REG. U. S. PAT. OFF.)

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is the most powerful motor in the country that is thoroughly perfected and tried out. Sturtevant motors are used by the U. S. Army and Navy and all the leading aeroplane builders.

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I 4-cylinder, 50 H. P. er s,zesi6-cylinder, 80 H. P.

Specifications upon request

m B. F. STURTEVANT COMPANY Hydt Park, Boston, Mass. H


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