Latham at that time had his Antoinette monoplane at Blackpool. It consisted of large and strongly built wings, giving a surface of about 575 square feet, set at a dihedral angle. The motor was some 60 h.p. At the back of the body of the machine were fixed horizontal and vertical fins. There were hinged horizontal planes at the end of the tail for elevating or lowering the machine. “Ailerons” were used on the main surface for controlling lateral stability. One day, at Blackpool, Latham went up in a very high wind, and remained in the air for a considerable time. How much of the stability of his machine was due to his dexterity, or how much to the machine, it is difficult to say. Probably the fact that the wings were set at a dihedral angle had much to do with it. He also had a much larger horse power than his contemporaries, which no doubt contributed to his success. Anyhow, by the Antoinette monoplane flight was redeemed from the reproach that it was merely a pastime for ideal weather conditions. From that time aviators have sought the winds as well as the calms. Now aircraft can fly in winds of forty-eight or even fifty miles an hour! This step of Latham gave a great impetus towards the military adoption of the aëroplane. The military and naval mind tends to despise what is only of use in the most favourable conditions. It had put aside the airship till it could combat moderate winds. It did the same with the aëroplane. The Wright, Farman, and Blériot machines may be described as the parent types from which have sprung the large variety which at the present time are at the disposal of the aviator. Amongst the various types which have sprung from the parent forms we search in vain for any underlying new principles, if we except the Dunne machine. There is, however, in the various types plenty of variety of constructional detail. Perhaps the two most important features of modern aëroplane work are (1), the gradual substitution of steel in place of wood, and the general strengthening of aëroplane construction; (2), the armouring of vital parts of aëroplanes for the exigencies of warfare. Of this latter innovation mention will be made later. Regarding the various types of machines now available, it must suffice in this chapter to especially mention a few which have features of special interest for the purpose of warlike operations. The success of the operations of the British aëroplanists in the war is evidence of the efficiency of the apparatus being used. The British military aëronautical authorities have evolved a very useful form of aëroplane. In present circumstances, however, detailed description of this must be omitted. WEIGHT-LIFTING MACHINES.