The desideratum, indeed, is the duplication of such a vital part as the motor. Considerations of weight have been the hindrance to engine duplication. Mr. Short has given very special attention to this matter, and has designed what appears to be an excellent machine, undoubtedly of military value. The biplane is supplied with two Gnome motors. One drives the screws in the front of the machine, and placed a considerable distance apart. The other drives a single screw behind the planes. In the ordinary way both engines run at moderate speed, but if one fails the acceleration of the speed of the other will keep the machine flying. THE VENDÔME MONOPLANE. A monoplane which has repute in France for strength, general aptitude, and convenience is the Vendôme type. It has been especially commended by experts on account of the quickness with which it can be put together and dismantled. The only criticism to which it has been exposed is, perhaps, that it is a little too strong for requisite lightness, and that a modification of the metallic portions might reduce weight without sacrifice of efficiency. This machine throughout is made of hickory wood. BREGUET-BRISTOL BIPLANE. This is one of the newest machines France has at her disposal. It is a happy combination of British and French make, due to the collaboration of two firms, the Bristol Company and La Société Breguet. The result of the combination is said to be eminently satisfactory. A distinguishing feature of this machine is rapid dismantlement. There are two pairs of wings. These are identical, interchangeable, and connected in each case by a flexible partition, which permits of the wings being laterally straightened up. The area of this interesting machine is 39 square metres; length, 8.90 metres; span, 11.50 metres. THE DESTROYER NIEUPORT MONOPLANE. During this year, even before the outbreak of war, the aëroplane had been well armoured and armed. A striking example of an armoured air-scouting machine is the Nieuport monoplane. This type has obtained brilliant result. Equipped with pilot, bombs, and armament it has flown at the rate of 145 kilometres an hour, risen at the rate of 500 metres in 3 minutes 45 seconds, made its departure and landed within an enclosure of 150 square metres. This monoplane has 24 square metres of surface, and weighs more than 1,000 kgs. The armoury is carried out by a cuirass of steel or nickel plates, which cover the vital front parts and the place where the pilot sits. ARMOURED CLEMENT-BAYARD MONOPLANE. This new type is exceedingly well armoured, the protective caps covering the motor and the middle of the machine. The following are the dimensions, etc.:-- Length 5.60 metres Span 9.50 metres Area 18 sq. metres Motor 100 h.p. Gnome Weight 415 kgs. Speed 150 km. per hour