In endeavoring to describe the measures taken to meet the aircraft needs of the Navy and Army, the writer is at once confronted by the fact that the information desired by the country is precisely the information desired by the enemy. What the country wants to know is what has been the expansion in our Air Services; whether we have met and are meeting all the demands of the Navy and of the Army, both for replacement of obsolete machines by the most modern types, and for the increase of our fighting strength in the air; what proportion of the national resources in men, material and factories is being devoted to aviation; what the expansion is likely to be in the future. These are precisely the facts which we should like to know with regard to the German air service, and for that reason it would be inadmissible for us to supply Germany with corresponding information about ourselves by publishing a statement on the subject. It can be said that the expansion of our Air Services is keeping pace generally with the growing needs of the Navy and the Army. In Chapter VIII, under the heading:--"_The Ministry of Munitions in 1917_," the following is read:-- The number of persons engaged in the production of munitions in October, 1917, was 2,022,000 men and 704,000 women, as compared with 1,921,000 men and 535,000 women in January. They have thus been increased during the past six months at the rate of 11,000 men and 19,000 women per month. These numbers include those employed in Government and in private establishments, in the principal munition industries, chemical and explosive trades, engineering and munition plants, furnaces and foundries, in shipbuilding and in mining other than coal-mining. The total represents approximately two-thirds of the total labour occupied on Government work in industry. The preceding official statistics prove most conclusively that actually, and ever since the beginning of the third year of the war, more than _twelve millions_ of men and women--more than the fourth of the total population of the United Kingdom--have been either in the Armed Forces of the British Crown--Navy and Army--or in the shipbuilding yards, in munitions factories, in transportation on land and sea, in the Medical Service, in the Air Service, &c., employed for the success of the cause of the Allies. THE FINANCIAL EFFORT OF GREAT BRITAIN. The gigantic military effort of Great Britain, in all the branches of its wonderfully developed organization, as above illustrated, was only rendered possible by a corresponding financial contribution.