The interim report of Mr. Justice Bailhache’s Committee, issued early in August, 1916, said: ‘There has been an enormous expansion of the Flying Service since the war; and all the critics of the Service, without exception, have borne testimony to the great progress made in its efficiency—a progress which, although most noticeable since the beginning of this year is, in the opinion of the Committee, the result of many months of strenuous work. To this efficiency the recent reports from the front bear eloquent witness.’ Early in September, 1916, one who enjoyed facilities for visiting flying centres, and learning at first hand of the progress of aviation in the country, remarked that ‘there was no need to be an expert to appreciate the remarkable change that had come over certain districts, where, what a few months ago were mere country villages or stretches of pine wood, have been transformed into industrial centres, with as many signs of bustle and industry as are to be found in the great shipbuilding centres of the British Isles. ‘A really remarkable thing is the enterprise and adaptability of firms who had never tackled the job before in organizing their work so that Britain’s output of machines was marvellously increased. Now the fruits of long and costly experimental work are being reaped, and the rate of output increases every week. This applies not to one establishment, but to the hundreds of works throughout the kingdom. So much is this the case that a country which at the beginning of war was believed to be behind in this branch of warfare is able not only to supply its own needs but also those of its Allies.’ The same careful, persistent, and unobtrusive research work that has brought British aircraft to the top has also resulted in great improvements in the construction and invention of bomb sights and dropping appliances. British engines, too, are now second to none in point of power, and great improvements are to be recorded in carburettors and special appliances for flight at high altitudes. The same progress is to be recorded in the matter of speed. The average speed of aeroplanes as used by our Air Service two years ago was from sixty-five to seventy miles per hour. Nowadays it is much higher. As regards the future, a British officer remarked at the time now in mind: ‘With all the results achieved so far, and the knowledge gained by this great war, there is no reason to doubt that the British Air Service—like the British Navy—will be the premier in the world. That is our constant aim.’ CHAPTER XVI AIR SUPREMACY The great Somme offensive proved beyond all dispute the claim of England and France to the supremacy of the air. It is not, however, always clearly understood precisely what air supremacy means. To that remarkably able war correspondent, Mr. Philip Gibbs, we owe one of the clearest accounts given of the part played by aircraft in modern warfare.