These orders for 4,200 guns and the orders for 2,026 howitzers placed at the same time brought the total number of guns and howitzers under manufacture in England for naval and merchant service purposes in May, 1917, up to the high figure of 10,761. At the end of the year 1916 the total number of merchant ships that had been armed since the commencement of the war (excluding those which were working under the White Ensign and which had received _offensive_ armaments) was 1,420. Of this number, 83 had been lost. During the first six months of 1917 armaments were provided for an additional 1,581 ships, and during the last six months of that year a further total of 1,406 ships were provided with guns, an aggregate number of 2,987 ships being thus furnished with armaments during the year. This total was exclusive of howitzers. The progress of the work is shown by the following figures: Number or guns that had been Date. provided for British Merchant Ships excluding Howitzers. January 1, 1917 1,420 April 1, 1917 2,181 July 1, 1917 3,001 October 1, 1917 3,763 January 1, 1918 4,407 The figures given include the guns mounted in ships that were lost through enemy action or from marine risks. It should be stated that the large majority of the guns manufactured during 1917 were 12-pounders or larger guns, as experience had shown that smaller weapons were usually outranged by those carried in submarines, and the projectiles of even the 12-pounder were smaller than was desirable. Of the 2,987 new guns mounted in merchant ships during the year 1917 only 190 were smaller than 12-pounders. AIRCRAFT FOR ANTI-SUBMARINE WORK _Anti-submarine work by aircraft_ was already in operation round our coasts by the beginning of 1917, and during the year the increase in numbers and improvement in types of machines rendered possible considerable expansion of the work. Closer co-operation between surface vessels and aircraft was also secured, and as the convoy system was extended aircraft were used both for escort and observation work, as well as for attack on submarines. For actual escort work airships were superior to heavier-than-air machines owing to their greater radius of action, whilst for offensive work against a submarine that had been sighted the high speed of the seaplane or aeroplane was of great value.