the rotary type, in lightness and ease of fitting into the nose of a fuselage. The majority of machines were tractors (propeller in front) although a preference, which died down subsequently, was still shown for the monoplane over the biplane. This year also saw a great increase in the number of seaplanes, although the 'flying boat' type had only appeared at intervals and the vast majority were of the ordinary aeroplane type fitted with floats in place of the land undercarriage; which type was at that time commonly called 'hydro-aeroplane.' The usual horse power was 50--that of the smallest Gnome engine--although engines of 100 to 140 horse-power were also fitted occasionally. The average weight per horse-power varied from 18 to 25 lbs., while the wing-loading was usually in the neighbourhood of 5 to 6 lbs. per square foot. The average speed ranged from 65-75 miles per hour. III. PROGRESS ON STANDARDISED LINES In the last section an attempt has been made to show how, during what was from the design standpoint perhaps the most critical period, order gradually became evident out of chaos, ill-considered ideas dropped out through failure to make good, and, though there was still plenty of room for improvement in details, the bulk of the aeroplanes showed a general similarity in form and conception. There was still a great deal to be learnt in finding the best form of wing section, and performances were still low; but it had become definitely possible to say that flying had emerged from the chrysalis stage and had become a science. The period which now began was one of scientific development and improvement--in performance, manoeuvrability, and general airworthiness and stability.