There was when War broke out no realisation on the part of the British Government of the need for encouraging the enterprise of private builders, who carried out their work entirely at their-own cost. The importance of a supply of British-built engines was realised before the War, it is true, and a competition was held in which a prize of L5,000 was offered for the best British engine, but this awakening was so late that the R.F.C. took the field without a single British power plant. Although Germany woke up equally late to the need for home produced aeroplane engines, the experience gained in building engines for dirigibles sufficed for the production of aeroplane power plants. The Mercedes filled all requirements together with the Benz and the Maybach. There was a 225 horsepower Benz which was very popular, as were the 100 horse-power and 170 horse-power Mercedes, the last mentioned fitted to the Aviatik biplane of 1917. The Uberursel was a copy of the Gnome and supplied the need for rotary engines. In Great Britain there were a number of aeroplane constructing firms that had managed to emerge from the lean years 1912-1913 with sufficient manufacturing plant to give a hand in making up the leeway of construction when War broke out. Gradually the motor-car firms came in, turning their body-building departments to plane and fuselage construction, which enabled them to turn out the complete planes engined and ready for the field. The coach-building trade soon joined in and came in handy as propeller makers; big upholstering and furniture firms and scores of concerns that had never dreamed of engaging in aeroplane construction were busy on supplying the R.F.C. By 1915 hundreds of different firms were building aeroplanes and parts; by 1917 the number had increased to over 1,000, and a capital of over a million pounds for a firm that at the outbreak of War had employed a score or so of hands was by no means uncommon. Women and girls came into the work, more especially in plane construction and covering and doping, though they took their place in the engine shops and proved successful at acetylene welding and work at the lathes. It was some time before Britain was able to provide its own magnetos, for this key industry had been left in the hands of the Germans up to the outbreak of War, and the 'Bosch' was admittedly supreme--even now it has never been beaten, and can only be equalled, being as near perfection as is possible for a magneto.