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The Scientific American Flying Machine Trophy—That Prize—G e r m a n Motor Prize—Blue Hill Meteorological Observatory—Aero Club of America—Resistance of Air to Planes—Aeronautical Motors —Ludlow Aeroplane—St. Louis Dirigible and Gasless Machine Prizes—Gordon Bennett International Contest—Chronology —Baldwin Dirigible—Aeronautic Calendar—Notes—Dufour Glider—Correspondence—New Aeronautic Books—Aeronautics in the Current Magazine s— Collection on Aeronautics :: :: :: ::
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REPRESENTING THE AERO CIA'B OF AMERICA
the scientific american trophy for flying machines of the gasless type
American magazine of Aeronautics.
PUBLISHED MONTHLY BY
AMERICAN MAGAZINE OF AERONAUTICS CO.
Ernest LaRue Jones, Editor and Owner 142 West Sixty-Fifth Street, New York, U. S. A.
Vol. I September, 1907 No. 3
American Magazine of Aeronautics is issued promptly on the tenth of each month. It aims to furnish the latest and most authoritative information on all matters relating to Aeronautics. Contributions are solicited.
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THE SCIENTIFIC AMERICAN TROPHY FOR FLYING MACHINES OF THE GASLESS TYPE.
In presenting- to the Aero Club of America the handsome trophy which forms the frontispiece of this issue, the proprietors of the Scientific American have sought to stimulate progress in the science of aerial navigation not only in our own country, but throughout the world. They have endeavored to accomplish this by making the trophy an international one, open to competition annually by anyone who has a heavier-thau-air (gasless) machine which shows itself capable of flying under its own power. It is intended to make the conditions of the annual contests progressive in character so that they shall as far as is possible, be always a step in advance of what has been or is being done in the line of aerial navigation by heavier-than-air machines at the time of the various contests, Uy making the prize more difficult to win, each year, it is thought that a practical Hying machine will eventually be evolved, Besides being open to international competition, there is a provision to the effect that the trophy shall become the property of anyone who wins it three times in different years. Thus a special inducement is given to the winner of the first contest to improve his machine, if, necessary, in order to win two of the subsequent contests. That the lirst one may not be too difficult of accomplishment, yet that it may be somewhat in advance of what has already been publicly done, it was decided to have this competition for a flight of one kilometer (^,280 feet) in a straight line. The first competition will be held at the Jamestown Imposition on the 14th instant, and at least one aeroplane—that of Israel Ludlow—is expected to compete.
This new aeronautical trophy is the handsomest and most valuable one that has ever been offered for an event of this kind. The trophy perpetuates
in silver the Langley model aeroplane, which was the first self-propelled model to fly half a mile, this distance having been covered above the Potomac river in May, 1896. That the machine invented by Prof. Samuel P. Langley was by no means the failure it was painted is evidenced by the fact that Bleriot, in France, has recently made several successful short flights with a machine of this type, fitted with only a 24 H. P. motor, while Santos
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Dumont, with his double surface machine, required 50 H. P. and has recently raised this to 100. Because Langley, with his model aeroplane, was the pioneer, it was thought but fitting that his name and his machine should be perpetuated. Hence, in the Scientific American trophy, Laugley's model is seen soaring through the clouds, with the sunlight breaking through upon it. The globe represents the firmament, the heavens being shown on the
front and the Xortli American continent on the back. Stars are seen peeping through the clouds and several birds are vicing with the aeroplane in flight. On top of the globe, which is supported on a whirlwind rising from a suitable pedestal, a large American eagle bearing a wreath of victory, has just alighted. On each side of the pedestal base, graceful winged horses spring forth, ridden by male figures bearing aloft olive blanches. As can be seen in a measure from the photograph, the trophy is a very beautiful affair. One needs, however, to see this handsome piece of silver itself to appreciate completely its beauty of design and execution. It stands 32 inches high over all and is valued at $2500.00; but its real value is much greater, for it will serve to encourage and stimulate invention and improvement in that most recent and interesting of sciences, the science of aerial navigation.
In the July number we appealed to our readers for a cash prize in competitions of "gasless" machines. We asked for a considerable amount, we know, but we indulged, perhaps unfortunately, in a belief that there might be enough wealthy sportsmen who would appreciate the aid that such a prize would lend.
In making the amount as large as we did we thought that this great United States would be able to devote
to such a purpose when little countries like France and England can each offer prizes of $50,000. Though personal applications have been made to man}r to subscribe toward such a prize we have thus far met with failure.
To repeat—the proposition brief]}' is somewhat as follows: There are hundreds of inventors of aerial apparatus, good, bad or indifferent. Among them all there may be something of value. The majority are devoting their earnings and their spare time to experiments on a small scale. After reaching a certain point they can go no further for lack of funds. They cannot obtain funds from capitalists for the reason that no one is willing to expend money until he sees a good chance of getting it back—with interest. Now, then, we have the inventor, the idea, the capitalist. We want to get them together. If the capitalist sees that by expending a few hundreds on further experiments he may gain a few thousand he is willing to take a chance. Tf we have the prize hung up we have the incentive. An inventor with a possible machine can say. "Mr. Capitalist, there is that prize. 1 think 1 can win it. Will you risk, say. $500 or $1,000?" The capitalist then has something to figure on. But until we get this prize the inventor cannot reach the capitalist.
We have in mind a man who believes he has something practical. That belief is nothing new. Hut we believe he has something at least worth a trial. The machine, moreover, it is claimed, is complete and awaiting final flight. The inventor desires, in case he makes a successful night, to be reimbursed, at least, for his expenditures. He asks that a prize of but $5,000 be offered contingent upon his flying 1,000 feet. Such a flight would be the record
public flight to date by a "gasless" machine. This attempt is desired at the earliest moment.
We mention this instance as a case in point. No one is prepared to say whether this or that machine may not be developed into something practical. If the prize is not won the donor, or donors, will not be losers. If the prize is won, they will still be gainers by the knowledge that they have made possible an actual demonstration of the practicability of dynamic flight.
Are there not in this broad land of ours some men whose purses are likely to leak along philanthropic paths?
GERMAN $5,000 MOTOR PRIZE.
A German aeronautic society has offered prizes to this amount to induce German inventors to work on light motors. The prizes are restricted to German manufacturers and the motors must be of 20 h.p. Major Gross, Prof. Klingenberg and Major von Parseval are members of the committee.
Out of three hundred members there are a bare dozen who have made actual balloon flights. The rest have been deterred—by what reason? Among other objects the Club was formed to promote the sport of ballooning, but the members have failed in the majority to take advantage of the opportunities offered.
In order to provide a greater inducement, a movement is on foot to purchase new envelopes for the Centaur and Orient and have as many members as possible make trips. It is planned to appoint pilots who will offer their services without charge, and to furnish the balloon and gas at a flat rate of, say, $20, to any member making his first ascent, the Club paying the balance of the cost of gas and miscellaneous items. Thus a member having never before made an ascent can do so at a sole outlay of $20, in addition to his railroad fare. The balloons will be stationed at some advantageous point, probably Pittsfield, and returned there after each ascent. Applications to be received and accepted in the order of receipt. In case the member fails to use the balloon on the date assigned he forfeits the $20 deposited with the application. Alan R. Hawley is the promoter of the scheme and it is one to which every member should lend his aid. To provide the necessary sum to enable the Club to do this it is suggested that members be assessed $5 each. Mr. Hawley feels that he has done his share towards the promotion of this most delightful of all sports and is anxious to see some competitors for long distance honors.
Philadelphia also might be a suitable location for a permanent aerodrome. There is good gas to be obtained there and the situation of that city is excellent. It is no nearer the sea than many ballooning centers abroad and one can run down in two hours from New York after telephoning to have the balloon ready upon his arrival. There is no time lost in going a great way from New York and, perhaps, after arriving, having to wait for a breeze. We attend to our daily business right along and on finding a good breeze after breakfast, telephone, answer the morning's mail, take the train and we are off the ground shortly after our lunch in Philadelphia.
ATMOSPHERIC EXPLORATIONS CONDUCTED BY THE BLUE HILL METEOROLOGICAL OBSERVATORY.
At the Milan meeting of the International Commission for Scientific Aeronautics it was decided to concentrate the work of exploring the air this year upon four grand series of ascensions, in addition to the usual monthly ascensions. The former last several days and observations are to be obtained not only by balloons and kites but also by special observations of cloud drift and upon mountain summits. The first of these quarterly ascensions was appointed for the week commencing July 22d. and, as has been the case for several years, co-operative kite-flights and cloud observations were made at Blue Hill Observatory. It is supposed that the United States Weather Bureau Station on Mount Weather, Virginia, which has recently taken up the work of exploring the free atmosphere, also participated in this series of ascensions. Unfortunately, light winds prevailed on Blue Hill during almost the entire week, so that but four kite-flights were possible and only on the 27th was the height of a mile and a half attained. During an evening flight, the top kite and the meteorograph broke away, and the latter has not yet been recovered. Had a small steamer been equipped for kite-flying in Massachusetts Bay, as was done for the first time by Professor Rotch in 1901, the kites would have been rendered independent of the wind by the motion of the vessel either in the direction of the wind or against it, for, in order to lift the kites, a velocity of at least 14 miles per hour is required, which is more than the average velocity of the wind in Summer on Blue Hill. Kiteflying was continued during the following week in more favorable conditions and of the three flights, the highest on August 2d reached an altitude of nearly two miles.
Although no efforts were made in America to secure observations over the ocean, as was done abroad. Professor Rotch, the Director of Blue Hill Observatory, and a member of the International Commission, extended his field of work by ^ending Mr. Clayton to the White Mountains to obtain observations in the free air at the height of Mount Washington and on that mountain itself. Such an investigation had already been conducted privately by Mr. Ferguson of the Blue Hill Observatory, who had installed self-recording instruments on the summit of Mount Washington and at Twin Mountain Stations for the purpose of comparing the conditions on the mountain with those shown by instruments lifted by kites to the same height. Between July 21st and 28th Mr. Clayton obtained three such series of observations with kites at a height exceeding that of Mount Washington (6300 feet), and on the days when the wind was too light to lift the kites, he carried the instruments up the mountain. The records seem to indicate a greater wind velocity on top of the mountain, and probably a lower temperature, than in the free air.
Professor Rotch intends to resume the work of exploring the air at great heights by sending up more sounding balloons from Saint Louis next October, the successful experiments already conducted there being described in the first issue of this magazine. The situation of Blue Hill on the Atlantic coast precludes the use of balloons, but Saint Louis has proved an excellent place for this work. It is intended to make the ascensions during the first half of October so as to include the third, which is the date fixed for the international observations.
A LETTER TO AERONAUTS.
The American Magazine of Aeronautics is very desirous of obtaining accurate and complete records of all balloon and airship flights made in America during each month.
We would appreciate it very much if you would send us such records at the end of every month and we would be very glad to supply you with the blank forms for the purpose upon request.
May we not expect to hear from you?
AERO CLUB OF AMERICA.
Will you not kindly send the Club accurate records of all ascensions made in order that our file may be complete? The number of our delegates to the International Congress is directly dependent upon the number of trips made. As a matter of Club interest every one is urgently requested to promptly report their voyage?, and as detailed as possible. Blanks will be supplied to those who have not already received same. AUGUSTUS POST,
Aug. i.—A. L. Stevens and William F. Whitehouse in the ''Stevens No. 20,'' 623 cu. metres, at Pittsfield, Mass. Ascent at 12.08 p. m., descent at 12.33 p. m. Gas very poor and no ballast or instruments could be carried. Mr. Whitehouse's first ascent. Initial flight of new balloon.
Aug. 7.—A. L. Stevens in the "Stevens No. 20," at Pittsfield. Ascent at 1.15 p. m., descent at East Windsor 3.01 p. 111. Gas very poor. Distance 19 miles.
Aug. 29.—A. L. Stevens and William F. Whitehouse in the "Stevens No. 21," 1000 cu. metres, at North Adams. Ascent at 2.50 p. m., descent at Som-ersville, Conn., 6.55 p. m. Distance 50 miles. Initial flight of new balloon.
Aug. 29.—Alan R. Hawley in the "Stevens No. 20," 623 cu. metres, at North Adams. Ascent at 2.43 p. m., descent at Indian Orchard 6 p. m. Distance 43 miles. All ballast used.
ON THE RESISTANCE OF AIR TO THE MOTION OF PLANE
SURFACES By Otto G. Luyties.
As our atmosphere is so light a medium it is apparent that aerial navigation will ultimately be accomplished successfully by utilizing its inertia rather than its buoyancy.
Reaction devices of many kinds have been suggested, including aeroplanes, orthogonal flyers, flapping machines, helicopters and so forth. Even dirigible balloons are reaction devices in so far as they depend upon the inertia of air for the resistance to their propellers, while they are themselves retarded by the inertia of opposing air currents.
For these reasons I hope that the following discussion of the pressure of a frictionless elastic fluid upon a relatively moving plane will be of especial interest to aeronauts.
If a plane surface be moved normally relative!}' to a fluid such as air the impinging particles will offer a certain resistance. The power required to overcome this resistance will be the pressure times the a'clocity
and will be equal to the change in the energy of the air particles or half their mass times the square of their velocity. We may write this
I1 v = i in v2
The mass of the air will evidently be the weight of the air per unit of volume divided by g and multiplied by the area and the velocity so that
(w \ 2 w i -A v lv = - A v g / 2g
P = — A v
In the above deduction we assume that the entire kinetic energy of the air particles is employed in resisting the advance of the plane. We furthermore assume that the particles exert no other effective pressure on the plane.
It is, however, conceivable that certain particles would rebound with an energy equal to that of their impact. Such particles would exert a double pressure due to reaction as well as impact. Every particle rebounding in this manner, however, will collide with one still approaching the plane and either counterbalance its energy, or deflect it from its path. Therefore, under the assumption of a double pressure due to reaction as well as impact, the number of striking particles will be reduced by one-half, so that the total pressure on the plane will be the same under either assumption.
The peculiar action of rebounding particles colliding with others still approaching we may refer to as interference. This action will be most pronounced in the case of normal planes and will be negligible in the case of sharply inclined planes, the rebounding particles falling in with the prevailing stream lines. This is an important consideration in deducing the pressure on inclined planes.
Suppose that a plane makes an angle a with the line of its progress. It will then be foreshortened in proportion to the sine of this angle, the number of particles whose path is blocked being reduced in such proportion.
The en erg)' of the impinging particles will accordingly be
E — - A sin a v
But the particles will rebound from the plane with an equal energy
w . :i
E = ~ _ A sin a v r 2g
making an angle « with the plane on the other side of the normal.
The power acting on the plane will therefore be the resultant of these two; namely,
/ w A
E =1- A sin a v |2 sm a
» V 2g /
The direction of action of this resultant power will be normal to the plane as the components arc equal and symmetrically disposed. Therefore, the pressure on the plane will be normal, a peculiar fact which has long been known from experiment.
To find the pressure on the plane we observe that the normal pressure times the normal motion equals the normal resultant of the energy.
V v = E
1 V11 n
In this case, however, Vn is much less than the velocity of the particles
as an inclined plane progresses normally only in proportion to the sine of the angle.
V = v sin a 11
( ^ A
P V = P v sm a =1 - A sin a v I
i n i \2g /
2 sm a
( w A
P =1- A v 12 sin a = P X 2 sin a
1 V2g /
Tlie pressure of a frictionless elastic fluid on a relatively moving sharply inclined plane is accordingly equal to the pressure on an equal normal plane moving at the same speed multiplied by twice the sine of the angle of inclination.
The pressure on an inclined plane is, however, affected by interference, such interference increasing with the square of the angle.
As we have already shown this interference in the case of a normal plane will be equal to half the total pressure we might otherwise expect. It will therefore be numerically equal to sin 2 a when the full normal pressure is expressed by 2 sin <7.
The normal pressure on an inclined plane is accordingly
v 2 / 2 \
= - A v I 2 sin a—sin a )
2g V /
This is a general formula for plane surfaces which will be found to agree reasonably well with experiment at any angle.
Substituting the value of the pressure on a normal plane we find
= P ^ 2 sin a—sin
The accompanying table gives the normal pressures for various angles as computed by the new formula compared with Langley's experimental results and with the formulae and figures of several other investigators.
It is apparent that the new formula agrees most closely with Langley's and Thibault's figures and that it is of comparatively simple form.
On further consideration it becomes apparent that the interference is very small for small angles so that sin2 a is negligible for planes of very acute inclination.
For these we may write
P = 2 P sin a
For small angles, furthermore, 2 sin a is essentially equal to 2 «
sin i°. The sine of one degree is approximately one sixtieth, so that we obtain
P (2 P a X -j- )= P — V 60/ 30
This formula should be very convenient and is correct within 10% for angles up to 150, which is well within the limits of our accuracy at present.
The pressure 011 a 50 plane for instance will be -£-0 — J- and on a io° plane will be = 1'3 of the pressure on a normal plane.
It appears incidentally that the question of interference brought up in this article should be further analyzed, as it undoubtedly has an important
bearing on the well known shifting of the centre of pressure with changes in the angle. The amount of interference probably differs for various curvatures of the surface and for different outlines and various ratios of height to breadth.
The purpose of this article, however, has been to discuss the question of the presstire of an elastic frictionless fluid on a relatively moving plane and to derive a general formula, which we have found to be
From which we obtain the ratio
And for small angles
— A v ^2 sin a—sin : ratio P = P^2 sin a—sin
P, IN TERMS OF P
La il gl ey
La ngl ey
Resultant Ì Recorder /
Component \ Recorder j
2 sin a—-sin a 2 sin a
1 + sin a
2 sin a ( 1 4- cos a) 1 -f- cos a -f- sin a
(4 -I- 7T) sin a 4 -f- 7t sin a
2 sin a a
30" sin a
15° 20° 30° 45°
.300 .440 .570 .7S0 .910
035.166.318.451,-567.700, .914, .98
035,. 174 .347 .518
033 .167 .333 .500
5S1 .789 1.000
312 .500 .7071 .866
I 17 .250
* Intended for small angles only.
AERONAUTICAL MOTORS. It is intended to publish in each number a description of the various light motors now on the market which are
adapted for use in dirigible balloons and heavier-than-air machines.
The lightest motor in the world is now made by the Antoinette people. The ioo-hp., 16-cylinder motor to be used in the new Santos-Dumont aeroplane weighs complete but 130 kg. (286 lbs.) This motor develops, brake test, 123 hp., which brings the weight per horse-power down to 1.05 kg. (2.3 lbs.)
Almost as light is the Pelterie aviatic motor of 35 hp., weighing slightly less than 100 lbs., or, per horse-power, 2.8 lbs. The Automobile has this to say about it:
"Its arrangement is unique in that the six cylinders composing it are mounted on a crankcase barely long enough to accommodate two of their size were they placed in the ordinary manner. This
also greatly simplifies the engine by making possible the employment of a two-throw crankshaft, each group of three cylinders acting upon a common crankpin. Air-cooling is employed, of course, and the cylinders, which are set at an angle of approximately 90 degrees to one another, are also staggered so that each one gets the full benefit of a direct cooling current. Considerable ingenuity has, of necessity, been exercised in the arrangement of the valve-operating mechanism, the three push rods for the front group of cylinders being of the usual type employed in connection with rocker arms, while the
pelterie. other three are jointed and operate at
an angle as shown, the inlet valves being of the automatic type. No details of the dimensions of the motor or of its speed are given, though the latter as well as the compression must naturally be high in order to produce its rating of 35 horse-power. It is of considerable interest as demonstrating to what lengths light weight and compactness 111 a}' be carried where the internal combustion principle is applied to the design of a motor for aeronautical purposes.
A STORY WITHOUT WORDS.
The trial of the new Ludlow aeroplane in Hampton Roads, off the Jamestown Exposition, during the month of August.
Copyright by the Jamestown Official Photograph Co.
The aeroplane mounted on pontoon boats about to be launched. Captain t. t. l^ovelach in his bathing suit ready for the ride.
Copyright by the Jamestown Official Photograph Co.
Towed by the t\ S. naval tug Totomac across Hampton Roads: theaeropiane
passes in front of the battleships at anchor.
Copyright by the Jamestown Official Photograph Co.
The aeroplane's nose goes down into the water, the rear rises upward and the experiment comes to an untimely end due to the waterlogging of the pontoons.
THE LOST ORATOR. (Time of the Lost Chord)
Seated one day in my airship,
I was weary and ill at ease, As my gas-bag drifted idly
Over the waving trees; I knew not what I was doing.
But I heaved a sand-bag then. And it struck on a farmer's shoulders
And he cussed nothing like amen.
His oaths came through the twilight And punctured the evening's calm;
At handling deck-hand language This Reuben could take the palm;
His words told of pain and sorrow And desire to take my life;
All because of that innocent sand-bag He was bent upon bloody strife.
I have tried, but I try all vainly,
To arouse those sounds divine, But 1 always dump my sand-bags
On some milder fellow's spine; Tt may be some other balloonist
Will hear that talk again, And will write it on fireproof paper,
With a patent asbestos pen.
DIRIGIBLE BALLOON AND HEAVIER-THAN-AIR MACHINE
CONTESTS AT ST. LOUIS.
It is expected to bold competitions for dirigible balloons and gasless machines on October 22, at St. Louis. The *Scientific American trophy is available for competition, as well as the cash prizes offered by the St. Louis Club. These competitions will be conducted under the auspices of the Aero Club of St. Louis, which has appropriated the sum of $5,000.00 for aeronautical competitions and exhibitions, to be participated in by dirigible balloons and by aeroplanes, or any heavier-than-air vehicles for navigating the air, which are absolutely free in their flight, after their start has been made, and which require no permanent or visible connection with the earth.
The subjoined rules have been adopted to govern the competitions, the Aero Club of St. Louis reserving the right, however, to amend or alter the same at any time prior to a formal entry being filed, or subsequently. In the latter event, persons who have entered' shall have the right to withdraw if they do not consent to the amended rules and their entrance money shall be refunded. The club also reserves the right to promulgate, as occasion may require, minor rides or regulations not inconsistent with the general rules.
General Rules and Regulations. I.
(a) The competitions will be open to all forms of vehicles without limitations as to the power employed or the mechanical principles involved, except as hereinafter specified.
(b) All vehicles admitted to the contests must be absolutely free in flight after the start has been made. No vehicle requiring any permanent or visible connection with the earth will be admitted.
(c) No vehicle can start unless satisfactory to the committee.
(d) All entries will close October 1st. If requested, entries will be considered as confidential until that date.
(e) As an evidence of good faith, an entrance fee of $10.00 will be required, which will be refunded when the contestant occupies the space assigned him with an apparatus conforming to the rules.
(f) Each vehicle shall carry at least one person in its flight.
The sum of $5,000.00, appropriated for prizes, will be divided into offerings for competitions in two classes, as follows:
Class A—Competition for dirigible balloons, open only to that particular form of vehicle.
Class B—Competition for aeroplanes and other heavier-than-air vehicles of any form which have no gas bag attachment.
Class A—The sum of $2.oco.oo will be given the competitor who. in strict accordance with the rules, shall make the round of the course with a dirigible balloon in the best average time, and the sum of $500.00 will be given to the competitor who. in strict accordance with the rules, shall make the round of
*Rules of competition for this trophy were printed in the August number.
the course with a dirigible balloon in the next best average time. No prize shall be awarded any vehicle in this class which does not cover the full course at lea^t once in continuous flight without touching the ground.
Class B—The sum of $2,000.00 will be given the competitor who, in strict accordance with the rules, shall make the longest or best continuous flight with an aeroplane or any heavicr-than-air vehicle admissible under the rules, and the sum of $500.00 will be given the competitor who, in strict accordance with the rules, shall make the next longest or best continuous flight with an aeroplane or any heavicr-than-air vehicle admissible under the rules. The committee in making its decision has the right to consider the average height, distance, time and general behavior of the vehicle, together with its merits for practical use. No prize shall be awarded any vehicle in this class which does not make a continuous flight, without touching the ground, of at least 100 feet.
(a) In no event will more than one award be made to any one vehicle.
(b) If it shall appear at the ch se of the trials that two or more competitors have equal records, the Aero Club of St. Louis reserves the right to prescribe a further trial or trials under the same rules and regulations governing the preceding contests.
(a) The prescribed course will begin and end in or adjacent to the enclosure of the Aero Club of St. Louis.
(b) The course will be triangular in shape and will have a total length of about three-quarters of a mile, the start and finish being made from the home goal. The course will be marked by captive balloons or in such other way as the Aero Club of St. Louis may deem best adapted to define the goals.
(c) Each competitor will be permitted to choose the direction in which to start, but he shall start from the home goal, turn around each of the outer goals, and return to the starting point.
(d) The time occupied in a trial will be measured from the moment the vehicle, entirely free from the ground, passes across the line at the starting goal to the moment of passing over the home goal.
(a) The trials shall take place on or about October 22nd, the exact date to be fixed later by the Aero Club of St. Louis, who shall also have the privilege of extending the time for the tests from day to day, as deemed necessary or advisable.
(b) The average speed of the machines shall be computed for the actual air-line distance over the ground, making no allowance for the wind or the deviations from straight lines to or from the established goals.
(c) The judges may, in their discretion, permit a contestant to go over the course more than once in continuous flight, and in such event the average time of such trials shall be considered the time made by such contestant.
(d) If any mishap or accident should occur to a contestant or his vehicle after the start is made, the judges, in their discretion, may permit another trial.
(e) The time for the trials shall be set by the committees in charge of the competitions.
(f) The conduct of the contest will be in charge of a committee or committees to be appointed for that purpose by the Aero Club of St. Louis.
(g) The Aero Club of St. Louis will provide a suitable enclosure for the aeronautic grounds and defray all necessary expenses connected therewith, but each competitor must provide any special structure or apparatus recpiired by his entry at his own expense.
GORDON BENNETT INTERNATIONAL RACE. St. Louis, October 21, 1907. Arrangements.
The postponement of the James Gordon Bennett International Aeronautic Cup Contest to be held at St. Louis was made necessary by the inability of the Laclede Gas Light Company of St. Louis to supply the proper quality of gas on the date originally set. The race was to have been held on Saturday, October 19th, while the date now fixed is Monday, October 21st. The gas for the balloons is to be supplied from a large holder on Chouteau and New-stead avenues—a few blocks removed from the ascension grounds in the east end of Forest Park.
This holder supplies a large section of the City of St. Louis with its gas. Ordinarily the gas stored in it is a mixture in which water gas predominates. As water gas has much less ascensional power than coal gas it was necessary to make arrangements for providing coal gas for the race. The Laclede Gas Light Company held that in any ordinary week day the demand on them for gas is so great that they could not possibly put the Chouteau holder out of commission for two or three days.
It is necessary to empty this holder of all the ordinary illuminating gas it contains and then to re-fill it with coal gas made with a special reference to its lifting power. Saturday afternoon and Sunday are the only days, the company held, when it could make this change.
Now that consent has been obtained for changing the date of the race from Saturday to Monday, it is the plan of the gas light people to commence emptying the holder on Saturday afternoon of its regular illuminating gas and as soon as it is thoroughly free of the water gas mixture, to re-fill it with the special quality of coal gas that is to be made for this aeronautic race. The holder will be filled to its capacity Sunday and on Monday the balloons will be supplied from it. In this manner the holder will only be out of commission for general use one busy day—Monday—as Saturday afternoon and Sunday are holidays.
It is the intention of the Gas Light Company to commence the manufacture of special coal gas of high lifting power a month or so before the race takes place. All of the Company's coal gas will be made of that particular quality during this period, so that everything will be in perfect working shape when the time for the race comes round, fn this way, the company expects to give the contestants a quality of gas of considerably more lifting power than is usually supplied them. The greatest pains will be taken to produce the most perfect gas for balloon purposes that it is possible to make from coal.
The Aero Club of France has named Maurice Mallet as their member of the Contest Committee.
The line-up to date, as received by cable and unconfirmed, is as follows— ii balloons:—
France......Aero Club of France, 2 balloons. Pilots, Alfred LeBlanc and
Rene Gasnier. Aides, M. Mix and Chas. Levee.
England.....Aero Club of the United Kingdom, 3 balloons. Pilots and aides,
Hon.. C. S. Rolls, Griffith Brewer, Prof. A. K. Huntington, J. T. C. Moore-Brabazon, Lord Royston and Mr. Moore-Brabazon.
Germany.. . . Deutscher Luftschiffer-Verband, 3 balloons, namely, "Dusseldorf,"' "Pommern" and "Schwaben." Pilots and aides, respectively, Hauptmann von Abercron and H. Iliedemann, Oscar Erbsloh, llerr Meckel.
America.....Aero Club of America, 3 balloons. Pilots, Lieut. Frank P. Lahni
(alternate Major Henry E. Hersey) in the "United States," Alan R. Hawley in the "St Louis" and J. C. McCoy in the "America."
Hon. C. S. Rolls, Griffith Brewer, Prof. Huntington, Hauptmann von Abercron, Oscar Erbsloh, Lieutenant Lahni and Major Hersey were contestants in last year's Gordon Bennett.
The entries of Spain and Italy have been thrown out by the Federation Aeronantique Internationale on technicalities.
Aug. 6. Bleriot makes two consecutive flights of 122 metres (400 feet) and 143 metres (469 feet), each without coming to r.jst. The aeroplane landed on the ground between the jumps, but continued Pight after running about 12-metres (39 feet). On landing after the second flight the propeller blade and shaft were broken. Equilibrium is maintained by the movements of the operator.
Aug. 9. Elmer Van Vranken, of Gloversville, N. Y., makes a flight lasting; 40 minutes in a dirigible built by the Steele Manufacturing Co. After executing various manoeuvres the return trip was begun against a strong head wind. A short distance from the point of start some one seized the drag rope, and, despite protests,- pulled the ship to the ground. In all, five miles were covered.
Aug. 10. The French military balloon "Patrie" makes a flight from Paris to the country seat of the President of France at Rambouillet, fifty kilometres (31 miles). Making a landing on the lawn, the four officers pay an hour's, visit and start off again at a speed of 60 kilometres (37 miles) an hour.
Aug. 14. The Hague Conference forbids the throwing of explosives front balloons and airships in war, it is reported.
Aug. 18. Capt. Thos. S. Baldwin makes first public flight with his new-twin screw dirigible.
Aug. 23.—Carl E. Myers makes initial flight in his new collapsible dirigible "No. 23" at Saginaw, Mich. An i8-mi!e wind drove the ship a distance of six miles from the start. On the wind lessening, the return was successfully made under power.
Aug. 24. The "Ben Franklin," the largest balloon in this country, makes its initial flight at Philadelphia. It has a capacity of 2,600 cubic metres (92,000 en. ft.) of gas, accommodates twelve persons and carries 150 bags of ballast. Six persons ascend and travel a distance of 160 miles.
Aug. 27. The German military dirigible and the Parseval ship make simultaneous trips, the various manoeuvres lasting several hours. It is claimed that the nights of this day excelled the past work of the French Patrie.
THE NEW BALDWIN DIRIGIBLE.
Captain Thomas S. Baldwin's new airship is a radical departure from old methods in at least one particular. The principal feature is the double propellers, placed one behind the other. Captain Baldwin claims actual increased ֥fficiency in addition to, in this way, doing away with the torcpie. The following illustration shows the two propellers.
The engine is of the vertical type, four cylinders, air cooled, weighing 100 pounds, with a rated horse-power of fifteen. Mr. G. H. Curtiss. the builder of the motor, states: "It is evident that when these large engines are used some arrangement must be made to do aivay with the torque. In some of our ֥xperiments we have had frames turn up in a horizontal position from the resistance of propellers whirling in opposite direction. In addition to this advantage, the twin propellers have a stronger pull than the single propeller. As you will note from the photo, they are placed one in front of the other, and are operated by a shaft within a shaft instead of reverse gears to reverse motion of the rear propeller and turn it at the same speed in opposite direction. It appears to us that with the high speed engines this construction will be absolute!}' necessary on any dirigible balloon."
The first flights at Hammondsport were most successful. In the illustration shown below, Mr. Cur.tiss is the operator. The first public flight was made by Captain Baldwin at Schuetzen Park on Sunday, August 18, in consid-
G. H. Curtiss in tite Baldwin Ship.
erable wind, during which flight, though short, he executed several manoeuvers and found his ship at all times under perfect control. The landing was made within a few feet of the starting point.
Sep. ii. Conference of the eleven clubs comprising the Deutscher Luftschiffer-Verband, at Diisseldorf.
Sep. 12. Annual Conference of International Aeronautic Federation at Brussels.
Sept. 14. Competition of gasless machines at Jamestown Exposition for
the Scientific American Trophy. Sep. 15. International Race at Brussels. Sep. 20. Grand Prix at the Tuileries, Paris. Oct. 2i. Gordon-Bennett International Race at St. Louis. Oct. 22. Competitions for Cash Prizes offered by Aero Club of St. Louis
and for the Scientific American Trophy. Oct. 28. Aeronautic Congress at Jamestown Exposition. Nov. 15. International Exposition of Aeronautic Photographs, at Paris.
Twenty balloons are entered for the French club's Grand Prix Sept. 29.
Lieut. Lahni has written for Outing Magazine for October an article on "Ballooning and Aerial Navigation."
Cortlandt Field Bishop, President of the Aero Club of America, will sail for America on October 2, on the Kronprinzessin Cecilie.
Both Strobel and Baldwin have announced their intention of competing for the St. Fouis Club's dirigible prize.
Cortlandt Field Bishop expects to bring over with him a new balloon for his own use.
According to "Le Matin," the French government is asking for funds to build three more airships of the "Patrie" type.
Count von Zeppelin is rushing work on his new airship in order to complete it before the International Congress at Brussels September 12-15.
Major B. Baden-Powell's "Ballooning as a Sport" should be read by every one at all interested in ballooning or intending to take up the sport.
Col. Max C. and Mrs. Fleischmann and Mr. Stevens made an ascension from North Adams on September 5th.
Lincoln Beachey during the month of August, at Jamestown Exposition, made 11 successful flights in his dirigible. The U. S. Government has detailed 10 soldiers for duty at the Aeronautic Building.
Col. Max C. Fleischmann, of Cincinnati, has written for the September Cosmopolitan an account of his experiences hunting in Africa and the Far North. Now for ballooning!
While the balloon of Russell E. Gardner, member of Aero Club of St. Louis, was being inflated on August 30. a team attached to a tallyho became frightened and ran into it. The balloon is a total loss.
On August 31 a cable was received to the effect that England's dirigible which has been building at Aldershot for the last two years, is about to be completed. It is said to approximate the type of La Patrie.
From the latest reports it looks as though Wellman will have to delay his polar trip another year. We wonder what will be found to delay next year's start.
E. B. Bronson has written for the October "American Magazine" an interesting description of a balloon voyage back in '74 which lasted 26 hours, a record for twenty-five years, in which he took part and of which he is the last survivor. The article is entitled "An Aerial Bivouac."
J. B. Pursell, of Chattanooga, has been working on a machine somewhat along the line of Santos-Dumont. A fire destroyed the greater part of it a few days ago.
On August 29 a wind storm struck the Iowa State Fair Grounds, blowing an electric wire against Knabenshue's airship, which caught fire and was ֤estroyed, together with a captive balloon which he was operating.
In last month's "Chronology" it was erroneously stated that Bleriot made a flight of 165 yards. He made one flight of 125 metres and another one of nearly T50 metres, the distance being measured by M. Archdeacon.
Germany is now worried over the possibility of France obtaining details of her fortifications, etc., by means of airships. Alarmists are urging the passing of laws prohibiting foreign airships from navigating the free air above German land, and authorizing the destruction of such trespassers by ''artillery or otherwise."
Discovery—"Do you expect to discover the North Pole?"
"Not immediately," answered the arctic explorer; "for the present I am content with discovering new methods of discovering the pole."—Washington Star.
Does this refer to Wellman?
Cleveland Moffett will describe in the October number of McClure's the remarkable tactics by which Frank P. Lahm won the International Balloon Race in Paris, when America, competing against the greatest countries of the world, captured the famous Gordon-Bennett trophy, and thus brought it to this country.
Automotor Journal for August 24 has cpiite a lengthy article on the effect of wind on the speed of automobiles. Wind screens of various sizes, solid surface and gridiron, were placed on automobiles and time over a measured course taken. The figures obtained at various rates of speed are of practical interest to the aeronautical experimentor.
Joseph A. Blondin expects to start October 12, from Albuquerque, N. M., on a long distance trip in his new balloon, competing for the Lahm Cup. The start will be made at sunset and, figuring on the prevailing winds, the anticipated course is toward northern Texas, Colorado or Kansas. Hydrogen gas will be used and a trial made of two devices for economizing ballast which Mr. Blondin has invented. This should be an interesting trip, especially in view of the rare atmosphere at the start.
To carry out his part of the wager with Archdeacon, Santos Dumont is now at work on a hydroplane which he promises will make 100 kilometres an hour. The boat is cigar shaped, about 10 metres long, with the greatest diameter well forward. A 16 cyl, 12S h.p. Antoinette motor will supply the power.
Of considerable information to the aeronaut was a lecture recently given
in London which was illustrated with moving pictures of various birds in flight, starting flight, landing, etc. We believe this is the first time that an attempt has been made to secure pictures showing the continuous movements of various large birds.
Going the new de la Vaulx portable airship one better, Mr. Myers of Frankfort has devised and had in operation a complete dirigible which is veritably a "pocket edition." The bag folds up into a package two feet square the car forming another 20 x 20 x 30 inches, and the 36-foot frame reduced by telescoping to form a rack 8 feet long by 22 inches triangular section, weighing but 32 pounds. On August 23, at Saginaw, Michigan, this airship, which he has named "No. 23." attempted a flight in an iS mile wind, against which the 7 hp. motor was not quite able to propel it. The wind slowly drove the ship back a distance of 6 miles where a landing was made at 7 p. m. Later the wind died down and at 11 o'clock the ship was back in Saginaw under its own power.
A. Q. Dufour. of 717 Cass St., Milwaukee, Wis., is experimenting with a gliding machine having the following characteristics: g feet long by 22 feet wide, the two planes being placed 4 feet apart; a rigid tail-piece 6 by 7 feet; elm framework, which he has found to be flexible and tough with small weight: mounted on four 14 inch rubber tired wheels; total weight, 120
pounds; operator, 150 pounds; 6 angle planes have maintained good equilibrium. To obtain momentum the inventor utilizes an inclined runway dropping 1 in 4 feet, 15 feet from the ground at the lower end, 40 feet long. Owing to the comparative great weight of the operator the glides have been short.
Carl F. Myers has for some time past been conducting some experiments at his "balloon farm" at Frankfort, X. Y., for the purpose of ascertaining how long hydrogen gas can be retained in a balloon without appreciable loss, the handling and decanting of gas from one vessel into another speedily and the operation of captives and airships for long periods exposed to all variations of weather. The extremes of hot, cold and rainy days were experienced during the early part of July when the rainstorms even wrecked buildings in the vicinity. Beginning the week of July 4th Mr. Myers operated a captive balloon, making a free flight in it in the late afternoon of July 4, landing for the night and starting again in the morning. The balloon was in practically
Photo by H. K. Klein.
Photo by E. E. Klein.
dufour machine in flight.
continuous use during five days without being re-inflated. Since Jul}' 6th this balloon, with others, has been almost continually inflated out of doors exposed to all weather.
On Monday, July 29, a motor airship was substituted, with which the same evening a Mr. Coughlin, of Dayton, made several flights to learn its ֣ontrol. Tuesday evening the same ship made several flights for further practice. Wednesday the gas from this ship was turned into another of exactly the same pattern and Mr. Coughlin left for Dayton with his ship, where he will use it for exhibition purposes, the other ship remaining out of doors. Up to August 2d the envelope was still tight. The fierce hail-storm of this date, no harm to the envelope and no gas was lost.
Editor, American Magazine of Aeronautics, Xew York City.
M3* work with internal combustion motors has been entirely in connection with automobiles, but the reading of the article on light engines by Mr. Harry E. Dey in the latest issue of your periodical has brought up several points, regarding which I desire enlightenment. I realize that motors for this purpose may be radically different in design from automobile motors, for constant instead of varying speed is desired, and the freedom from road shocks permits the reduction of weight in webs, braces, etc.
The present development of these motors has been due almost entirely to the growth of the automobile industry, and the makers have devoted a vast capital of cash and time in the improvement of efficiency. Their goal has been the production of a .motor of the greatest power for the least weight, and T should think that the results of their researches might be taken as the starting point in the design of a motor for airship work.
An internal combustion motor derives its power from the action of the heat units contained in the fuel, and the greater the volume of the charge that is drawn into the cylinder, the greater will be the pressure developed by its combustion. The compression of the charge is, of course, a great factor, and the more the charge is compressed the greater will be the pressure developed, for the expansion of the gases will then occur within a more limited space. The advantage of compression, however, does not lie in this to the extent that is commonly believed, for its chief importance is that it provides a means of making the charge more uniform. Tests have shown that even the best of carburetors furnish a most imperfect mixture, and that a considerable proportion of the gasoline enters the cylinder, not as vapor, but as liquid in a finally divided condition. The function of a carburetor is not the mixing of the air and gasoline, but their proportioning, and the action in the cylinder during the compression stroke is depended on to combine the two elements, and to render the mixture more uniform.
The maker of an automobile engine strives to take into the cylinder the largest possible charge, and to compress it as highly as is possible without danger of preignition; to reduce the volume of the charge and to compress it to a greater extent, as suggested by Mr. Dey, would be against his principles. The limit of practical compression for air cooled engines is accepted as being from 50 to 55 pounds, a higher compression resulting in preignition. Preignition from high compression results in combustion so quick as to be almost a detonation, and this is a condition that must be scrupulously avoided. Combustion by the propagation of the flame, following ignition by spark, is comparatively slow, but ignition by high compression occurs in all portions of the charge at practically the same instant, and the pressure would be developed so suddenly that the piston—or cylinder-head would probably blow through before the inertia of the piston could be overcome.
To reduce the volume of the charge taken into the cylinder means the reduction of the number of heat units available, and a consequent lowering of the initial explosion pressure; the volume of the charge has nothing to do with the extent to which it may be compressed without danger of preignition. Unless the application of an internal combustion engine to the
propulsion of an air ship contains elements so subtle as to be understood only by the initiated, the reduction of the charge as a means of increasing the power would hardly seem logical.
The use of an automatic iidet valve as against the mechanically operated type seems a step backward to one familiar with automobile work, for experience has shown the necessity of providing a positive mechanism. A spring cannot be classed as positive, even when it is kept cool; and when it is enclosed in the inlet pipe, as the spring of an automatic valve mn.-t be. the chances against its remaining in proper adjustment for any length of time arc greatly increased. The action of a mechanically operated valve is positive, being controlled by the action of a cam, and b}- a heavy spring that is exposed to the cooling action of air currents, and automobile makers arc unanimous in their conclusion that the automatic valve is erratic, difficult to adjust, liable to stick, and not dependable. It is true that the use of an automatic valve means a reduction of weight, but it would seem to be at the expense of safety.
A long connecting rod will increase the efficiency of the engine, but will also increase the weight. Economy in the use of fuel is desirable, but when it is obtained at the increase of the weight of the engine it would seem a doubtful expedient. Greater length of connecting rod results in less piston side thrust, but this may be obtained with a short rod by off-setting the crank shaft. This reduces the side thrust during the power stroke, while in-creasing it on compression, and as the expansion pressure is higher than compression pressure, the crank shaft may be offset until the side thrust is equal for the two strokes.
The use of steel for cylinders has been the subject of much experiment, for its use in place of cast iron in saving of weight and smoothness of surface are obvious; but the difficulties of lubrication and the tendency to lose a true circular form have precluded its adoption. If the heating were uniform, It might be a different story, but for cylinders of practical size, the difference in temperature between the two ends has resulted in twisting and warping. In this connection, the use of a cast iron piston in a steel cylinder might be questioned, for the difference in their co-efheients of expansion, (untempered steel .00001198, cast iron .00001234) would indicate a liability of the piston to sieze.
As I have stated, these comments are made from the automobile point ■of view, which prevents the free acceptance of the statements, but if the use of internal combustion engines for air ship work involves a deviation from ■accepted principles, I might suggest that the production of a successful and reliable motor for the purpose would be facilitated if automobile engine ■designers could be informed of the exact requirements.
ROGER B. WHITMAN, Technical Director. N. Y. School of Automobile Engineers.
Editor American Magazine of Aeronautics:
Will Mr. Samuel A. King, of Philadelphia, kindly let us know through your columns the dimensions of the balloon he used at Minneapolis in September. 18S1.
This balloon was claimed to be the largest ever constructed at that time. It certainly was a beauty, the form being simply perfect from an artistic standpoint, and it v. as a most inspiring sight to the fifty thousand people that witnessed the ascent.
I have often wondered why this bailor n is never mentioned among the big balloons of the past.
This balloon was filled with hydrogen, and it was the intention to make the trip from Minneapolis to the Atlantic Ocean. In addition to Mr. King there were several reporter* and a weather man. They became becalmed after going about half a dozen miles and descended to camo over night in a cow pasture half way between Minneapolis and St. Paul. A gale of wind came up in the night which lasted nearly a week. This caused them to abandon the trip.
My business at that time took me to Minnehaha Falls every day and I well remember the appearance from there of the great dome projecting so far above the tree tops. It was too bad to have a trip that was so well provided for, and started so auspiciou.-dy, .spoiled through somebody's fool idea of camping out for the night on Mother Earth.
HARRY E. DEV.
NEW AERONAUTIC BOOK.
The Development of Motor Airships in the Twentieth Century, by Major Gross, the Commander of the Royal Prussian Airship Battalion, illustrated. The solution of the problem of the dirigibility of airships has been more nearly approached by the present successful experiments with motor airships than at any previous period, especially with the Patrie and the Zeppelin. In this exposition a concise demonstration is given of the progress made with modern airships, especially the advantages and disadvantages of the present proposed three types—the rigid Zeppelin, the semi-rigid Lebaudy, and the pliable Parseval. The book is published by Otto Salle, Berlin, W. 30, price 1 Mark. Printed in German.
A REMARKABLE COLLECTION OF PRINTS, CUTTINGS, ETC., RELATING TO BALLOONS AND AERONAUTICS.
This comprises three volumes of loosely bound pages, 14 x 16 in., on which the items are mounted on one side only, and a portfolio containing about 40 large prints, water-color drawings, lithographs, etc., mounted on cardboard 22 x 15, also a miscellaneous collection of music, posters, caricatures, etc., relating to the subject.
Among the items in the collection are:
Genuine contemporary accounts and illustrations of early experiments and the first balloon ascents (1783). Six different contemporary illustrations of Lunardi's balloon (1784). Portraits of the following: Montgolfier (2 different), Charles (3), Dr. Black (2), Cavallo (2), Lunardi (4), Blanchard (2), Sadler (2), Garnerin (2), Green, and many others. Colored caricatures by Rowlands!>n, Cruikshank, and others. Autograph letters and signatures by Green, Coxwell, Simmons, Burnaby, etc. Complete illustrated article on "Aerostation" from Encycl. Londinensis. Many items printed at C. Clark's private press. Full illustrated accounts of Lunardi's and Blanchard's ascents (784), Major Money's descent in the sea (1785), Garnerin's parachute (1802), Cocking's parachute and accident (1837), Hampton's parachute (1839), Nassau balloon. Monk Mason's airship (1843), Henson's aerial steam carriage (1843), Coxwell and Glaisher's ascent (1862), "Le Geant" disaster, Franco-Prussian war, Arctic propositions. Loss of Air. Powell (1S81), Crossing of Channel by Burnaby (1882), Baldwin parachute (1888), Maxim's experiments, Lilienthal (1893), Andree's Polar balloon, Langley's and Phillips's experiments, etc.
The whole is carefully arranged in chronological order, and forms a complete history of ballooning and aeronautics from the earliest time to the twentieth century.
This collection is absolutely unique, and no amount- of money would be likely to secure a similar lot without years of trouble.
Tt is certainly one of the most complete collections on the subject in existence. It is now for sale at $600.
AERONAUTICS IN THE CURRENT MAGAZINES.
Everybody's for August contains an exceedingly interesting paper on "The Mystery of Bird-Flight," by Harold Bolce. The action of the various birds in rising from the ground, sailing and landing is discussed in a most sensible way. The article is particularly noteworthy for its photographs. Tt is not an exposition of a flying machine but a mere statement of curious facts and to the student of aviation it will provide new ideas.
AIRSHIP BALDWIN'S "CALIFORNIA ARROW"
The "CALIFORNIA ARROW" was the first airship, the one from which all the present airships have been copied, and has made more successful flights than all the others put together.
I GUARANTEE ALL MY EXHIBITIONS.
Last season, out of 53 starts I returned to the exact starting point 51 times.
at the ST. LOUIS EXPOSITION operated by Roy Knabenshue
at the PORTLAND EXPOSITION operated
by Lincoln Beachy
I have ballooned around the world twice, giving ascensions in almost every country you can think of, including North and South America, Europe, Asia, Africa, China, Japan, Australia, New Zealand, etc.
I design and manufacture, Free Balloons, Captive Balloons, Airships, and in fact everything in the hydrogen line of aeronautics. Information relative to dates and terms, cheerfully furnished upon request.
Send for my new book "UP IN THE AIR."
Captain Thomas S. Baldwin, Airship "CALIFORNIA ARROW"
Box 78 Madison square p. o. New York City.
FOR SALE—Complete Captive Balloon Outfit.
All sizes from smallest
models of lightest weight to largest captive or long vo}Tage vessels with or with-
Patent machine var-
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Patent I13 drogeu gas generator systems, complete, all sizes.
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Operated 2S years.
140 gas balloons for U. S. Government.
Instructions given. All sorts of experiments conducted.
Only American Institute of Aeronautics.
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carl e. myers,
FRANKFORT, N. Y.
AERONAUTICAL ENGINEER AND CONSTRUCTOR
AERONAUT LEO STEVENS
contractor to U. S. government
Box 181, Madison Square, new York
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