In mid 1908 Glenn Curtiss chief engineer and members of AEA, reengineered controls and wingtip ailerons for Baldwin’s Aerodrome No. 2 “White Wing.” Glenn Curtiss’ Aerodrome No. 3 “June Bug,” named by professor Bell, successfully raised and land c., 4 times on 21st June, and by the 25th flew twice, on the latter take-off sustained flight for 1,040 m (3,420 ft). The Aero Club of America received a request from AEA, for the Scientific American Cup, awarded too any aviator attempting a public flight at a distance of over 1 kilometre (3,280 ft): Wining a solid silver trophy and cash prize of $2,500. The Club avoiding grief from the Wright’s, cabled, advising on the situation in hand, and requested if they would be interested in the first attempt, Orville declined on 30th June, received 1st July. Curtiss’ was issued a licence by the Aero Club and authorised on America’s Independence Day 4th July. After a false start, on the June Bug’s second attempt raised off the ground, and sustained a control flight for 1.6 km (5,360 ft), in 1 minute 40 seconds. Accounts claim the Wright’s declined owing they were immersed, tying loose ends, acquiring a contract with the US government for their flying machine. According too the new rules would require, “install wheels” for take-off, eliminating a race track catapult launch for the ground, for the all knowing Wright’s this should’ve been trivial. Most highly, considering issues with their Flyer, feared an unsuccessful attempt would promote public humiliation, governments loosing interest, putting into question the US patent and claims. Supposedly the brother’s stated during 1905, they attempted countless of successful flights reaching distances of 38 km (24 ml), conveniently without official and questionable witnesses. The Wright’s were hastily informed on Curtiss winning the cup and $2,500 cash prize, congratulated him by sending a lawyers letter warning on patent infringement: “Their control system used for exhibitions or in a commercial way without authority.”
Prof. A.G. Bell 1915:— “Drome No. 3, Curtiss’ June Bug, was completed about the middle of June, 1908, and successfully flown about that time, at Hammondsport, N.Y. With respect to the construction and arrangement of the supporting surfaces and the balancing ailerons and the means for actuating the same, the machine was substantially similar to the “White Wing”. When the “June Bug” was first completed, we were disappointed that it did not fly well enough to enable the ailerons to be placed normally at a zero angle of incidence. The supporting surfaces seemed to be somewhat porous, and allowed the air to leak through. We corrected this leakage of air by varnishing the supporting surfaces so as to make them air-tight. The ailerons changed to a normal zero angle, change was made on June 25, 1908, or a day or two later. On July 4, 1908, it gained the Scientific American Trophy for flying the first measured kilometer under test conditions for a heavier-than-air machine. Conversion of “June Bug” into “Loon” in the fall of 1908, floats were added to the “June Bug”, converting it into a hydroaerodrome, where upon Mr Curtiss changed its name from the “June Bug” to the “Loon.”
LIST OF PAPERS PRESENTED MAY 17, 1908.
The following papers were read at a meeting of the Aerial Experiment Association held at the headquarters in Hammondsport, N.Y., May 17, 1908:—
- Description of Aerodrome No. 1, Selfridge’s “Red Wing” F.W. Baldwin.
- Description of Aerodrome No. 2, Baldwin’s “White Wing” F.W. Baldwin.
- Plans for an improved motor for flying machines G. H. Curtiss.
- A brief sketch of the progress of the Art of Aviation T. Selfridge.
- A query concerning the nature of the torque produced by twin propellers rotating in the same direction J.A.D. McCurdy.
- Some thoughts concerning the effects of atmospheric pressure upon aeroplanes A.G. Bell.
- Suggestions regarding the construction of light motors for use in flying machines A.G. Bell.
- Papers 1, 2, and 4 will appear in subsequent Bulletins. Nos. 3, 5, 6, and 7 appear in the present issue. A.G.B.
PLANS FOR AN IMPROVED MOTOR FOR FLYING MACHINES: by G.H. Curtiss. (Read May 17, 1908). While extremely light motors may not be absolutely necessary in order to make a successful heavier-than-air machine, it stands to reason that a light motor of equal strength and reliability would be of great advantage. Other parts of the flying machine could be made heavier or could carry more load in the shape of freight or fuel. The motors made by the Curtiss Company up to date have been the outgrowth of the cycle motor, and while they give as great power per pound weight as any motors which are now built for the trade, a much lighter motor of equal power can be built. In designing such a new motor, we may consider first the system of cooling the cylinders. For aeronautical purposes, it is evident that the air cooled engine has many advantages. The weight of the water and radiators alone is objectionable, then there is danger of leakage where light construction is used. It would be impracticable to carry a large supply of water where if air could be utilized, a supply is always at hand. I am satisfied that cylinders up to 3 # inches in diameter can be satisfactorily cooled with air. the power of the engine is therefore limited only to the number of cylinders. The type of multi-cylinder generally adopted is that of our eight cylinder engine which consists of two sets of four cylinders on the sane case at an angle of 90 degrees. 18 This construction gives perfect balance and good results generally. There is only one form in which anywhere near as many cylinders can be assembled with as little crank-case and shaft weight, and that is placing the cylinders in the form of a star with all the connecting rods attached to a single crank. With this construction, both the crank-shaft and crankpin can be run upon roller bearings which will add about ten per cent to the power of the engine, and do away with three-fourths of the crank-case and crank-shaft weight found in the eight cylinder “V” type. The two disadvantages of this type of engine are the difficulty of operating valves and lubricating the cylinders and bearings. The latter may be managed by forcing the oil through the shaft and connecting rods and feeding direct to each cylinder. Naturally the cylinder, or cylinders pointing down would get too much oil. While there is practically no way of preventing this, the trouble of fouling the plugs may be prevented by placing the min the sides of the cylinder and the exhaust valve in the end. The surplus oil which goes in these cylinders would then be blown out with the exhaust. The placing of the valves in the head would also help out greatly in the cooling of the cylinders, and a blast of air blown across-wise would keep them sufficiently cool to allow its being run continually. The overheating of the exhaust valve can be prevented by using the same valve on the intake stroke, the in rushing gas keeping it cool. I believe that we can build a 35 horse-power engine of seven cylinders 3 ½ × 4 placed at equal distances apart around a crank, each cylinder fitted with a single valve in the head; the gasoline being fed mechanically to each cylinder, at a weight of approximately 75 pounds, and would stand up and give full power for ten hours running. The following sketch shows the general design of such a motor. The explosions take place in rotation as follows:— 1-3-5-7-2-4-6, making perfect balance and constant torque.
WORK OF THE AERIAL EXPERIMENT ASSOCIATION. As recorded in telegrams sent by members of the A.E.A.
Hammondsport, N.Y., June 19th, 1908:— Preliminary tests of running gear and surfaces were made to-day with aerodrome No. 3, Curtiss’s “June Bug”, which extended so late into the evening that there was no time left to make a flight. (Signed) Graham Bell.
To Charles F. Thompson, Supt. Associated Press, N.Y. Hammondsport, N.Y., June 20, 1908:— An unsuccessful attempt was made this evening to raise the aerodrome “June Bug” into the air. (Signed) Graham Bell.
To Charles F. Thompson, Supt. Associated Press, N.Y. Hammondsport, N.Y., June 21, 1908:— The Aerial Experiment Association aerodrome No. 3, Curtiss’s “June Bug”, made three successful flights here this afternoon with Mr. G. H. Curtiss as aviator. The first flight was 456 feet at the rate of 28.1 miles per hour; the second was 417 feet at the rate of 31 and one half miles per hour; the third was 1266 feet at the rate of 34 and one half miles per hour. This last flight is the longest yet made in public in America, and is only Mr. Curtiss’s fourth attempt. (Signed) Graham Bell. (Note:—Copies of Associated Press Dispatches written by Lieut. T. Selfridge after June 21, 1908 have not been received in time for this Bulletin. A. G. B).
To Mr. A. Graham Bell, King Edward Hotel, Toronto. Hammondsport, N.Y., June 25, 1908:— “June Bug” made record flight early this morning, 725 yards at an elevation of forty feet. Time 41 seconds. Wind 8 to 10 miles an hour blowing with machine. Tips worked beautifully and machine under perfect lateral control; front rudder inefficient, hence descent. 12 Surfaces have been revarnished and colored yellow stretching them tight and absolutely air proof. Nothing materially injured. Will try again this evening. (Signed) J.A.D. McCurdy.
To Alexander Graham Bell:— Prescott, Ont., or Kingston, care of steam-boat Toronto of R. O. Steam-boat Line, which left Toronto to-day at two P.M. for Montreal, and if too late to catch boat repeat to Windsor Hotel, Montreal, Que.
Hammondsport, N.Y., June 25, 1908:— Curtiss flew eleven hundred and forty yards, three thousand four hundred and twenty feet in sixty seconds this evening about 7.30. We have telegraphed and telephoned Secretary Aero Club of America that we are now ready to try for the Scientific American Cup. Hurrah! (Signed) Selfridge.
To Charles T. Thompson, Supt. Associated Press, N.Y., Hammondsport, N.Y., June 25, 1908:— Last night at about 8 P.M., Mr. Curtiss made two short flights. Owing to a strong side wind the machine was found to make considerable lee-way though with no tendency to tip. The fields in which the tests are being conducted is somewhat restricted by various obstacles except in one part. In order to clear these the machine must rise to a greater height than the experimenters deem prudent at this time, and as the drift caused by the machine necessitated flying over instead of around these obstacles, the tests were postponed till this morning. At 6 A.M. Mr. Curtiss made a beautiful flight of 725 yards in 41 seconds at the rate of 36.2 m per hour, running before a wind that varied between 6 and 8 miles an hour. The machine tipped sharply to port shortly after getting in the air, but was righted immediately be means of the tip controls, and kept on an even keel from then till the end of the flight. The surfaces had been revarnished and made completely air-tight since the last long flight. This increased the efficiency of the apparatus to such an extent that the motor developed too much power even with the spark fully retarded. Mr. Curtiss finally had to move his weight forward to aid the front control and keep the machine from climbing despite of this he reached a maximum height of 40 feet. Owing to this difficulty, Mr. Curtiss decided to discontinue his flight. This he did by shutting off the engine and gliding to the ground. No damage was sustained and the Aerial Experiment Association hope to try out the machine again this afternoon after the necessary alterations have been completed. This has been by far the most successful of all the flights to date. (Signed) T. Selfridge.
To Charles T. Thompson, Supt. Associated Press, N.Y., Hammondsport, N.Y., June 25, 1908:— G. H. Curtiss in his “June Bug” aerodrome No. 3, of the Aerial Experiment Association flew 1140 yards, 3420 feet in 60 seconds this evening about 7.30 P.M. The flight was stopped on account of the trees and a fence which limit the practice ground. This performance is the most remarkable on record, being only the seventh flight of the machine and the eight attempts by the aviator. The controls worked perfectly in every respect, the machine having to travel on the arc of a circle to be able to make this distance owing to the limits of the field. The height varied from 3 to 20 feet. The Aerial Experiment Association has just telephoned the Aero Club of America that it is now ready to try for the Scientific American Cup which is to be given to the machine that officially flies the distance of one kilometer in a straight line. This distance was surpassed to-night by 46 yards. All credit is due to the marvellously efficient eight cylinder Curtiss air-cooled motor which has never given the slightest difficulty and to the wonderful aptitude shown by the aviator Mr. Curtiss. There were several hundred spectators. (Signed) T. Selfridge.
To Charles T. Thompson, Supt. Associated Press, N.Y., Hammondsport, N.Y., June 27, 1908:— Mr. Curtiss again made two very successful flights here to-day of 400 yards in 24 seconds and 540 yards in 33 seconds at the rates of 34 and 33 miles per hour respectively. These flights were terminated at the will of the operator at a smooth place in the field in order to avoid running the machine back through the standing grain at the further end of the grounds. Their object was to test the efficiency of some alterations which had been decided upon. They proved all that had been expected and the machine is under better control than ever. It is hoped that the cup committee of the Aero Club will be able to come to Hammondsport as soon as possible as the Aerial Experiment Association has now been ready for it for the last three days. The Curtiss motor worked very satisfactorily. (Signed)T. Selfridge. To Charles T. Thompson, Supt. Associated Press, N.Y.
To Dr. A.G. Bell, Victoria Hotel, Charlottetown, P.E.I. Hammondsport, N.Y., July 2, 1908:— All arrangements made with Aero Club for trophy trials on July fourth at Hammondsport. (Signed) J.A.D. McCurdy.
To Dr. A.G. Bell, Victoria Hotel, Charlottetown, P.E.I. Hammondsport, N.Y., July 3, 1908:— Flew three quarters of mile to-night. Everything O.K. for July fourth. (Signed) J.A.D. McCurdy.
To Charles T. Thompson, Supt. Associated Press, N.Y. Hammondsport, N.Y., July 3, 1908:— The Aerial Experiment Association’s aerodrome No. 3, G. H. Curtiss aviator, made a flight of ¾ of a mile here this evening in 68 # seconds at 38 miles an hour. The machine traveled in a semicircle. The flight was one of several that were made in preparation for the official test of the machine which is to take place to-morrow before the Contest Committee of the Aero Club of America for the Scientific American Trophy. (Signed) T. Selfridge.
To Dr. A. Graham Bell, Victoria Hotel, Charlottetown, P.E.I. Hammondsport, N.Y., July 4, 1908:— Captured trophy to-day by flying distance of one mile in one minute and forty-two seconds. Flew full distance of valley. Came down on account of trees making beautiful landing. Machine under perfect control and everybody happy. (Signed) J.A.D. McCurdy.
To Charles T. Thompson, Supt. Associated Press, N.Y., Hammondsport, N.Y., July 4, 1908:— The Aerial Experiment Association’s Aerodrome No. 3, Curtiss’ “June Bug” to-day earned the right to have its name the first inscribed on the Scientific American Trophy, by making an official flight of 1 kilometer in a straight line measured from the point where it left the ground. After passing the flag marking the finish, the machine flew 600 yards further and landed at the extreme edge of the field near the railroad track, after crossing three fences and describing the letter, 2000 yards in all in 1 minute 42 ½ seconds at a speed of 39 miles per hour. This followed a 900 yard flight in 56 seconds.
The machine never behaved better and the long flight could have been continued at the will of the operator had he cared to rise over the trees which bounded the field. Though quite possible it was not deemed wise to attempt it at present stage of the aviator’s development. There was hardly a breath of air starting during either flight. This trial is really of the utmost importance as it is the first official test of an aeroplane ever made in America and there are only two other machines which have traveled further in public; Farman’s and Delagrange’s. The Wrights though have undoubtedly far outflown it in private so that America is not so very far behind France as might be supposed. The last flight to-day was the 15th made by the machine, all having occurred under far more adverse conditions than those encountered by the French machines. It is hoped that there will be several other names on the cup before the new year. In order to possess it, this trophy must be won at least once in three separate years. The rules being changed and made more severe after each trial. It is always i o pen for competition upon due notification being made to the Contest Committee of the Aero Club of America to whom it was presented by the Scientific American in the Spring of 1907. There are about 1000 witnesses among them being Messrs. Hawley, Post, Herring, Manley, Guy and Beach of the Aero Club. (Signed) T. Selfridge.
To Mauro, Cameron & Lewis, Solicitors of Patents, Washington, D. C. Charlottetown, P.E.I., July 5, 1908:— Please send some one to Hammondsport, N.Y. at once at my expense to examine the aerodrome of the Aerial Experiment Association which has just won the Scientific American Trophy for heavier-than-air machines. We want toknow what patentable features there may be about the machine. See Mr. Curtiss and report by mail to me at Baddeck, Nova Scotia. Take Lackawana or Erie train to Bath; local from there to Hammondsport. (Signed) Graham Bell.
To G.H. Curtiss, Hammondsport, N. Y. Charlottetown, P.E.I. July 5, 1908:— I have telegraphed Mauro, Cameron and Lewis of Washington to send patent expert to Hammondsport to examine “June Bug” and report to me what patentable features there may be about machine. Ask members of Association to give him every assistance. Accept our heartiest congratulations upon your magnificent success. (Signed) Graham Bell.
To J.A.D. McCurdy, Hammondsport, N.Y. Charlottetown, P.E.I., July 5, 1908:—Thanks for telegrams. I recommend postponing further experiments until machine has been examined by patent expert. Important to keep machine uninjured until then. Just off for Baddeck. (Signed Graham Bell.
To Charles T. Thompson, Supt. Associated Press, N.Y., Hammondsport, N.Y., July 5, 1908:— Before the departure of the judges and Aero Club Committee to-night, G. H. Curtiss before a crowd of several thousand people made an ascension in the June Bug and for the first time in the series of trials made a turn and faced directly toward the starting point. After covering # of a mile toward the starting point, it was necessary to fly over a vineyard and fearing disaster owing to the fact that he was flying low he brought the machine down with slight damage to the front control right wing. The flight and the maneuvers were considered a great success, it being the first attempt to describe a circle. The members of the Aero Club Committee expressed great satisfaction at the outcome of this trial. The aerodrome will be repaired to-night and experiments will he continued to-morrow. A number of the New York and Washington parties remained for the events to-morrow. (Signed) T. Selfridge.
To Aerial Experiment Association, Hammondsport, N.Y. Pictou, N.S., July 6, 1908:— If McCurdy wishes to follow on line of “June Bug”, I recommend that McCurdy’s machine be now built at Hammondsport and headquarters be retained there for the present. In meantime don’t run any risk of injuring “June Bug” until an application for a patent has been prepared. Would like Baldwin to help me in Baddeck soon as possible, and when we are ready for motor would like all to come to Baddeck. If these plans are acceptable would simply let it be known that at my request further trials of “June Bug” will be postponed until another aerodrome has been completed so that in case of accident to one machine another will be available for experiments. Would say nothing about patents outside as this would only stir up other inventors to forestall us in the patent office. Telegraph reply to Baddeck. (Signed) Graham Bell.
To Dr. A. G. Bell, Baddeck, N.S. Hammondsport, N.Y., July 7, 1908:— Meeting held on receipt of telegram. Decided to follow your suggestion, which was in accordance with McCurdy’s decision. Casey and wife start North in a day or so. (Signed) T. Selfridge.
To Aerial Experiment Association, Hammondsport, N.Y. Baddeck, N.S., July 7, 1908:—Thanks for telegram. Please write and telegraph Mauro, Cameron and Lewis, Washington, D.C. to send representative to Hammondsport if he has not yet appeared, and request representative to prepare an application for a patent at my expense. I will confirm matter by letter from here. Baldwin should not leave Hammondsport until he has given the patent expert what information he may desire concerning machines made in Hammondsport. First Bulletin of Association will be issued from here, Monday July 13, giving you full information as to what we are doing here. Please ask each member to write to me full account of what he is doing in Hammondsport, the information to be incorporated in succeeding Bulletins to be issued every week. In this way we can keep in touch with one another and incidentally secure written records of thoughts, ideas, and work done. Trouble will be saved here by sending six copies of any drawings or photographs illustrating letters. (Signed) Graham Bell.
WINNING THE SCIENTIFIC AMERICAN TROPHY JULY 4, 1908:— by G. H. Curtiss. Extract from letter to Dr. Bell dated Hammondsport, July 7, 1908. The affair of July fourth went off very nicely. There seemed to be some question, especially with the — representatives if we could fly the kilometer; and when we fell short on the first trial, Mr. B—who represented the — seemed to be pleased rather than disappointed. The machine was not flying as it should, and we discovered that the tail, which had been attached and detached a great many times, had gotten into a slightly negative angle which made it necessary to depress the forward plane to keep the machine on an even keel. This so greatly increased the resistance, that when it became necessary to slow the engine to prevent going too high the speed was slackened to such an extent that landing was necessary. In this trial, about half a mile was covered. After making the adjustment of the tail, she flew like a real June Bug; and just on account of Mr. B—, who was standing at the finish with a camera to photograph the machine in case I fell short on the distance, I flew the machine as far as the field would permit, regardless of fences, ditches, etc. We gave the Committee and Aero Club members a little outing on the Lake Sunday with the local band in attendance.
WINNING THE SCIENTIFIC AMERICAN TROPHY JULY 4, 1908:— by J.A.D. McCurdy. Extract from letter to Mrs. Bell dated Hammondsport, July 8, 1908. It was a dark day and the papers predicted rain, and it certainly did rain all through the morning, but towards three or four o’clock showed signs of clearing up. The pleasant-Wine-cellar people kindly threw open their doors to us and our visitors, and prepared a sumptuous lunch as one means of passing the dreary hours of waiting. Everybody was just as nice as they could be, and the crowd was most patient and sympathetic. About six the time seemed propitious, and the machine brought out of the tent, and the tail attached, the motor run, and everything carefully looked over. Manley measured the course in a straight line running right through the vineyard. Mr. Curtiss took his seat and the machine was rolled round to its starting point. After a few moments the motor was started, and the signal given to let go, amid a breathless silence on the part of the crowd. The June Bug sped down the track, and made a beautiful start, flew well, but short about four or five hundred yards. No damage was done however, so she was brought back and carefully looked over. This time we changed the angle of incidence of the tail slightly, making it more positive, we also re-wired the front-control. This time everything went serenely and not only did the June Bug reach the flags which marked the 21 2 finish, but, amid the rush and cheering of the throng flew six hundred yards or more further, to the limit of the field and made a beautiful landing on a smooth spot, absolutely unhurt in every respect. Everybody was almost crazy, and even Mr. H— appreciated the effort of the A.E.A. to fly. The town did all in their power to entertain our guests, and they all were delighted with their visit, and went back to New York with very happy thoughts of the visit which they will have every cause to remember.
To DR. A. G. Bell, Baddeck, N.S., Hammondsport, N.Y., July 9, 1908:— Mr. Cameron here for few days. Thinks we have severable patentable features. Had flight last night three-quarters of a mile. Its becoming an old story now. Will attempt complete circle to-night coming back to starting point. (Signed) J.A.D. McCurdy.
To Dr. A. G. Bell, Baddeck, N.S., Hammondsport, N.Y., July 10, 1908:— Made short flight to-night — distance one mile. Attempted to turn and land at starting point, but valley proved too narrow to accomplish this feat as yet. (Signed) J.A.D. McCurdy.
LETTER FROM MR. G.H. CURTISS, Hammondsport, N.Y., July 11, 1908:— I enclose a description of the “June Bug”, especially its differences from the “White Wing”, and the eight sets of prints — also the table of the eighteen flights I have made showing the distance covered, time, cause of stopping, etc. (Note:—The description of the “June Bug” will appear in a subsequent issue of the Bulletin. The table of eighteen flights is appended below, A.G.B).*** We have number 4 well under way. We have some good improvements in sockets for the struts and turn-buckles. The running gear seems to be pretty good — we have not broken it, although we have broken the front wheel twice. These were my only two bad landings. Made a mile flight last night, going around the hickory tree in the lower hayfield. As I wired you, Mr. Cameron was here and found a number of patentable features, including the tip controls, three wheel running gear, the combination steering of the ground wheel and rudder, and the shoulder movement which controls the wing tips. He has taken the data back to. (Signed) G.H. Curtiss.
Letter: (Extract from letter to Mr. Bedwin), Hammondsport, N.Y., July 11, 1908:— We have made a lot of changes in the machine; have shifted my position forward until I am 4 ½ feet further forward than on the Red Wing. The same old engine is still doing the pushing. We are getting up one with mechanical valves for B.B. (Signed) G. H. Curtiss.
AERODROME NO.3, CURTISS’S JUNE BUG, SHOWING HOW IT DIFFERS FROM NO.2: by G. H. Curtiss. (A letter to Dr. Bell), Hammondsport, N.Y., July 13, 1908:— The following is an enumeration of the differences between Aerodromes No. 2 & No. 3:— In No. 3 the wing tips were so set that when not in use, they were at a neutral angle while these in No. 2 when not working as controls were parallel to the surfaces. The gearing of the wing tips was simplified by the new arrangement of wiring necessitated by the operator’s seat being moved farther to the front. The main weights are separated by a greater distance in No. 3 than in No. 2. The engine was set five inches farther back and the man two feet farther to the front. The front control was also moved farther out and the front edge of it now 10 feet 10 # inches in front of the front edge of the main planes thus making the machine 27 ½ feet long. Five square feet have been added to the area of the front control, its total spread being now 13 feet 10 inches as compared with 11 feet 8 inches of No. 2. The nose is now wedge shaped instead of pointed and has been left uncovered. The running gear consists of three wheels as before, but the wheel base has been extended two feet. It has also been greatly strengthened by two large wooden members running fore and aft which are to be used as skids in case the wheels break down. The wings have been made so that they can be easily removed from the engine bed section and their surfaces have 16 been varnished with a mixture of gasoline, yellow ochre, parafine and turpentine in order to make them air-tight. The yellow ochre was used for photographic purposes. The working surfaces of the machine have been reduced from 408 to 370 sq. feet. Switch and spark controls have been placed on the front steering wheel. The lower plane has been greatly strengthened by eight guy wires fastening it to the hubs of the wheels and bottom of the skids. The engine section has been made up of lighter material, the struts being only ¾ of an inch thick at their widest part and 2 ¼ inches long instead of one inch thick at their widest part and 4 inches long as was used in No. 2. Additional guy wires have been added to this section and it is now more rigid than before. The propeller has been cut down from 6 feet 2 inches to 5 feet 11 inches, and is now turning up to about 1200 rpm., instead of 1050. The tail has been made spar-shaped from side to side so as to conform to the general shape of the main surfaces. The vertical surfaces of the tail have been removed and the area of the vertical rudder increased from 27 inches square to 36 inches square. It has also been decided to do away with the screw sockets for the vertical posts and to put turn-buckles on each socket. We are also to use balloon rubber silk for the surfaces. These last changes have not yet been made however. The distance between the center of gravity of the operator and the center of gravity of the engine is now 6 feet.
LETTER FROM MR. G. H. CURTISS, Hammondsport, N.Y., July 14, 1908:— I thank you very much for your letter of July 5th. I am greatly pleased myself that we were successful in accomplishing what we set out to do. I am satisfied that our machine is equal, if not superior, to any of the foreigners. I note in Mr. Farman’s contract that he specifies absolutely smooth fields, with no fences, or ditches and with grass cropped short. We have been working at a considerable disadvantage in this respect so that if we can fly a mile at a time, picking our way as we do, we could surely make a good showing over a perfect course where landing could be effected anywhere. I am glad that we are to build another machine as it will give us a chance to try out the twin propellers which we wanted to use on the No. 3, but which was given up to avoid delay. The twin propellers are what should be used on the tetrahedral where the greatest obtainable thrust will be needed.***(Signed) G.H. Curtiss. (Above letter was addressed to Mrs. Bell).
Letter: (Extract from Letter to Mr. Bedwin), Hammondsport, N.Y. July 20, 1908:— Everything O.K. on here. Are getting out material for new machine. Am making a few changes over June Bug. Giving greater lateral extension and larger tips. Having the body all covered in to reduce head resistance. Two propellers and stronger running gear. (Signed) J.A.D. McCurdy.
Telegrams: To Dr. A. G. Bell, Baddeck, N.S., Hammondsport, N.Y., July 26, 1908:—Made four short flights, Curtiss one, Selfridge three; landed safely; everything O.K. (Signed) J.A.D. McCurdy.
To Dr. A. G. Bell, Baddeck, N.S., Hammondsport, N.Y., July 27, 1908:— Had grand afternoon and evening work-out with June Bug. Had many trials. Longest flight brought machine and McCurdy to spot where Curtiss landed July 4th. Time one minute and forty-five seconds. Machine absolutely intact. Curtiss has gone to Washington. Tom leaves to-morrow night. (Signed) J.A.D. McCurdy.
To Dr. A. G. Bell, Baddeck, N.S., Hammondsport, N.Y., July 28, 1908 :— Tom in New York, Curtiss Washington. Made eight flights to-day, three of which took one minute and fifty seconds. Made turn but within six hundred yards of starting point. Flight about sixty feet above the ground. Machine intact. (Signed) J.A.D. McCurdy.
McCurdy to Bell, Hammondsport, N.Y., Sept. 6, 1908:— Made short jump to-night in June Bug using double-decker. Control 15 feet in front of main planes. Works beautifully. J.A.D. McCurdy.
A SUMMARY OF THE WORK AT HAMMONDSPORT LABORATORY FROM JULY 4 TO SEPT. 1, 1908:— by G. H. Curtiss, Director of Experiments.—As we have become more proficient in handling flying-machines, and desire to make longer flights, it is thought advisable to fit the number 4 with an engine having a surplus of power, and a positive cooling system. Such a type of engine would ultimately by necessary on all successful machines, therefore, we have decided to build and equip the number 4 with this motor. It is an eight cylinder, water-cooled, with a 3 ¾ bore, and four inch stroke. It will weigh about 160 lbs and be rated at 50 H P. Our shops are running night and day on this motor, for which the machine is practically ready. During the construction of the number 4, series of experiments have been carried on with the old “June Bug”, with a view of incorporating any improvements we could make in the latest machine. The tail has been entirely removed, one surface at a time. The removal of the upper surface seemed to have little effect, but with both surfaces taken away, and the frame only remaining, there is a marked difference in the handling Both Mr. McCurdy and I rode it in this way making short flights. After the first flight we became more accustomed to it, and finally learned to keep it on very even keel, and with the framework of the old tail entirely removed we have turned in a smaller circle than before. The principal advantage of removing the tail is the increase of speed, and it was decided to use no tail on number 4. To off-set the slight instability a new front control has been made, and placed o 1 7 feet forward of the main surface. This control has two surfaces 30 inches wide and eight feet long. A short flight was made last evening in which it appeared to work nicely and be a good improvement. Owing to the wind no turns were attempted. Another experiment was made in connection with the surfaces. This was to do away with the reverse curve. The original ribs had become flattened, making it necessary, if further flights were attempted, to make new ribs. In doing this we changed the form, and fitted ribs which were straight except for the usual curve at the forward end, which was slightly increased. An improvement both in lifting and in gliding was immediately perceptible. G.H.C.
This report was enclosed in the letter from Curtiss to Bell dated, Sept. 7, 1908. A.G.B.
Letter: CURTISS TO BELL. (About Orville Wright’s Machine). Hammondsport, N.Y., Sept. 7, 1908:— I have been down to Washington for two days, called there by a message from Gen. Allen. I was lucky enough to arrive just in time to see the Wrights’ flights, Thursday and Friday. The first flight was rather short as Mr. Wright said he was unaccustomed to the machine, and the levers seemed awkward for him. He made a wrong move and headed for the tent, which necessitated immediate landing; in this landing, with the machine tilted somewhat, one rudder struck first causing the machine to swing around sideways and broke the rudder off. The next day he did better, however, and made as fine a landing as you would make on wheels. The launching device, which includes a derrick, and a big weight which drops the pulleys and rope to give the initial velocity, does not seem to be very well liked, and I believe that all who have seen our machine and the Wrights’ prefer our method of starting on wheels to skids. I had some talk with Mr. Wright and nothing was said about his patents on adjustable surfaces. He has nothing startling about his machine and no secrets………..The engine is the same they had four years ago, being rather crude and not exceptionally light. Mr. Wright sits to the left of the engine just inside of the front surface on a little cushioned seat, which is large enough for two. Mr. Wright told me they intended to use but one propeller hereafter, presumably to simplify. This double-chain transmission they have weighs 100 lbs. more than the single propeller would. Selfridge has been ordered to St. Joseph, Mo. to fly the Government airship at the coming manoeuvres. After that he will probably fly the Wrights’ machine. Mr. and Mrs. Fairchild were out to the flight, and I had a nice visit with them. I enclose a brief description of what we have been doing here since the last report. G. H. Curtiss.
Curtiss to Bell, Hammondsport, Sept. 9, 1908:— Flew one half mile to-night with four cylinder improved June Bug. See letter. G. H. Curtiss.
Letter: Curtiss to Mrs. Bell. Hammondsport, N.Y., Sept. 9, 1908:— I had a short, but pleasant, visit with Mr. and Mrs. Fairchild in Washington the other day. I was there for two days in response to a message from Gen. Allen to get the Government’s motor ready for the St. Joseph tournament. One of the Wrights made a flight each day, the first and only two they have made so far. The first day’s flight was marred by a bad landing which broke one of the skids. The second was better lasting for over four minutes. It is plain to see that they have nothing new, or better than we. I wrote Mr. Bell describing the machine……G.H Curtiss.
Telegram: Bell to Orville Wright, To Orville Wright, Fort Myer, Washington, D.C. Baddeck, Sept. 11, 1908:— On behalf of the Aerial Experiment Association allow me to congratulate you upon your magnificent success. An hour in the air marks a historical occasion. Graham Bell.
Letter: CURTISS TO BELL, Hammondsport, N.Y., Sept. 11, 1908:— Explaining our message of yesterday, wish to say that as the weather was favorable and a number of out-of-town people were desirous of seeing a flight of the “June Bug”, I went to the track at six o’clock in the evening, took the machine out, and flew for the first time with the new rudder and front controls as per the illustration. The interesting feature of the flight was the fact that I had no sooner gotten in the air than four cylinders ceased running; caused by the breaking off of the gasoline pipe which feeds the four cylinders on one side. This pipe had been recently put in by the boys as they thought the old one might be too small. The big one did not stand the vibration I knew immediately what had happened, and thought it would be a good opportunity to see how near I could come to flying with only four cylinders running. To my surprise, I kept on going and I made a good hal n f mile, including quite a turn, with four of the eight cylinders working, which means that less than half the power was being developed. The number of revolutions did not decrease to the same extent, as the speed was over thirty miles an hour, and the propellers turned much more easily than when standing. The last Bulletin has been received and contents gone over carefully. I shall prepare to be present at the meeting called for Sept. 30th at Beinn Bhreagh, with my report. The summary of the experiments to date on the tetrahedral aerodrome, and the prospects for the No. 5, are most interesting and instructive. The recent flight of the “June Bug” with but four cylinders running, Mr. Wright’s flights of an hour alone, and shorter time with Mr. Lahm aboard, furnish data as to the power required in aerodromes of this type. By making deductions, required power for the tetrahedral-cell structure may be obtained with reasonable accuracy. With this information Curtiss Co. would be willing to undertake construction of a motor of sufficient power and light enough weight to accomplish the purpose. The engine for No. 4 will develop 50 H. P. and weigh, complete with the radiator and water, about 225 pounds. G. H. Curtiss.
Minutes by J. A. D. McCurdy, from September 21, 1908, to September 26, 1908:— A meeting was held on Sept. 20, 21st 1908, by order of the Chairman, at 1331 Conn. Ave., Washington, D. C. at 10 A. M. Present, A. G. Bell, G. H. Curtiss, F. W. Baldwin and J. A. D. McCurdy. On Sept. 26th, 1908, a meeting of the Association was held by order of the Chairman reviewed the conditions which led to the formation of the Association, its work during the past year and the probable plans for the Association in the future. Bell reminded members that the Association would come to an end on Sept. 30th, 1908, unless, as stipulated by our Constitution, a unanimous vote of the members was obtained which would decide otherwise. He also pointed out that we might have inventions which if of — a patentable nature would have some commercial value and, if so, the interests of the late Lieut. Selfridge would have to be considered in a legal fashion. Mr. Bell also stated that he had been authorized by Mrs. Bell to say that she would be willing to donate money as wanted by the Association to the limit of $10,000 more to allow the experiments to be carried on for another period of six months. The following resolution was put and unanimously carried:—
- RESOLVED:—that that the Aerial Experiment Association be continued under its present organization for another period of six months, ending March 31, 09.