Note on page 5 * The author is of opinion that although there may be nothing altogether inexact in this statement, it is, unless qualified in some way, capable of conveying an erroneous impression.

Note on page 5 * It is of interest to note that MM. Voisin and their staff are entirely responsible for the design of their machinée, and guarantee that they will fly. The purchaser pays for his machine in part as a deposit and the remainder when the machine has actually flown. It is time that the false impression that has been conveyed to the public by the press ehould be dispelled. Meeers. Delagrange and Farman (Voisin's first customers) had no more to do with the design of their machines than the purohaser of a motor car from the manufacturer.

Note on page 5 † So far as the author is informed, the “ triplane ” type of Voisin machine (Goupy 1) has not performed so well as the earlier model (Farman type), though this may be due to the short time that it has been in the hands of the aeronauts. The author believes that the three members of the aerofoil are relatively too close to one another for best efficiency : their aspect ratio also is not good. Beyond this the position of the propeller (in front) is one not conducive to the beet efficiency and the race of the propeller in such a position may materially add to the bodv résistance

Note on page 7 * It has been recently reported that the Wright machine has undergone alterations, by which it is enabled to rise from the ground by ite own power ; whether the machine has been fitted with permanent wheels, or whether it is mounted temporarily on a trolley, which it leaves behind when it rises, the account does not say; probably it is the latter.

Note on page 7 † “ Aerial Flight,” Vol. II. ; Aërodynamics, Ch. VII.

Note on page 7 * The rate of increase of altitude of a machine having a reserve of 40 per cent, would be quite sensational. Thus at 1,000 metres per minute velocity, the power required for horizontal flight may be represented by a loss of altitude of about 130 metres per minute, and an additional 40 per cent, would give an actual rate of ascent of over 50 metres per minute. The Wright machine does not, in the author's opinion, show so great a capacity of ascent. At the time of the author's visit a paseenger of about 60 kilos, weight was being carried, the machine should still have been able to rise at a rate of over one metre in two seconds.

It is on record that on one occasion Mr. Wright took up with him a passenger weighing 100 kilogrammes, but, on the other hand, on another occasion he failed after repeated attempts to raise another passenger of approximately this weight ; it may consequently be inferred that an addition of 100 kilos, to the 500 kilos. normally carried, that is, an addition of about 20 per cent., represents approximately the limit of the capacity of the machine.

Beyond this, Mr. Wright has admitted (at least to the author), that his gliding angle is about 7 degrees; this, at, a gross weight of 1,100 lbs., gives 140 lbs. thrust required, and at 58 ft. per SIT., the thrust h.p. becomes 14.5. Now Mr. Wright also agrees 24_b.h._p. as the power of his motor, which, if 40 per cent, in excess of his ro'iuirementa, gives 17.1 b.h.p. as ordinarily utilised, or the total efficiency of gear and screw propeller would be 85 per cent.—a manifest impossibility.

If Mr. Wright's statement may be taken to mean tha.t the thrust h.p. required is about 15 to 16 h.p., and that his reserve of power is 40 per cent, to include that lost in propulsion, then the whole matter is clear. It is possible that the author misunderstood Mr. Wright's meaning.

Note on page 9 * See account of speech at banquet given by Aero Club de France, New York Herald (Paris Edition), November 3, 1908.

Note on page 10 * “ Aerial Flight,” Vol. II., Aërodynamics, Ch. V and VI.

Note on page 11 * A certain patentee sent the author a specification of his invention, in which a rudder was carefully arranged to act spirally, to give a cant in the direction of the banking, that is, the direction in which the turnin? moment is already excessive. He might be well advised to take out another patent for the same device, arranged to act in exactly the opposite way !