A very remarkable type of aëroplane is the giant biplane invented by the Russian aviator Sykorsky. It doubtless marks the beginning of a new era in the construction of machines on the heavier-than-air principle. Most aviators have shirked the use of a machine that could carry a large number of persons. It would seem that Russia is destined to take the lead in this class of machine, which may before long put the lighter-than-air Zeppelins entirely out of date. The machine of Sykorsky is not, indeed, a mere project, but a reality, for at Petrograd on February 25th, it flew for eighteen minutes with sixteen passengers on board. They represented a weight of 1,300 kilogrammes. The height attained in this flight was 300 metres. On February 27th the machine flew from Petrograd to Tsarskoe Selo and back again, taking nine persons, in two hours six minutes, at a height of 1,000 metres. The performance constituted a triple record of distance, height, and duration of flight with nine persons on board. The following are the dimensions, etc.:-- Length 20 metres Span 37 metres Surface 182 sq. metres Distance between planes 2.80 metres Motive power 4 Argus motors (100 h.p. each) Weight of motors 220 kgs. Weight of machine without passengers 3,500 kgs. Weight with 16 passengers 4,800 kgs. The motors are placed in groups of two on each side of the body of the machine. Each pair works a screw and each individual motor can be put into action and stopped separately. The body of the machine contains a chamber for the pilots three square metres in size, a passenger salon of five square metres, and two other chambers of three and two square metres respectively. The whole are lit by four windows on each side. The rooms can be artificially lighted by electricity and warmed by motor gas. There are, indeed, future possibilities for such a machine in war! I have mentioned that the type of aëroplane devised by Lieutenant Dunne is characterised by a distinctive principle of its own. The claim is made that it is automatically stable. It has, however, rather a claim to “inherent stability” than “automatic stability,” if we accept the terms as Professor Bryan has defined them. The following details appeared in the “Aëronautical Journal”:--