of the difficulties experienced in its early days of development, and partly owing to the extensive outlay involved in fitting all ships.  However, this opposition was eventually overcome, and before the end of the war the system had very amply justified itself by saving a large number of warships from destruction by mines.  It was computed that there were at least fifty cases during the war in which paravanes fitted to warships had cut the moorings of mines, thus possibly saving the ships.  It must also be borne in mind that the cutting of the moorings of a mine and the bringing of it to the surface may disclose the presence of an hitherto unknown minefield, and thus save other ships.

Similarly, the “Otter” defence in its early stages was not introduced without opposition, but again all difficulties were overcome, and the rate of progress in its use is shown in the following statement giving the number of British merchant ships fitted with it at different periods of 1917: 

By July 1, 95 ships had been fitted. 
By September 1, 294 ships had been fitted. 
By December 1, 900 ships had been fitted.

The system was also extended to foreign merchant ships, and supplies of
“Otters” were sent abroad for this purpose.

A considerable number of merchant ships were known to have been saved from destruction by mine by the use of this system.

DEFENSIVE ARMING OF MERCHANT SHIPS

The defensive arming of merchant ships was a matter which was pressed forward with great energy and rapidity during the year 1917.  The matter was taken up with the Cabinet immediately on the formation of the Board of Admiralty presided over by Sir Edward Carson, and arrangements made for obtaining a considerable number of guns from the War Office, from Japan, and from France, besides surrendering some guns from the secondary and anti-torpedo boat armament of our own men-of-war, principally those of the older type, pending the manufacture of large numbers of guns for the purpose.  Orders for some 4,200 guns were placed by Captain Dreyer, the Director of Naval Ordnance, with our own gun makers in March, April and May, 1917, in addition to nearly 3,000 guns already on order for this purpose; 400 90-m.m. guns were obtained from France, the mountings being made in England.  Special arrangements were also made by Captain Dreyer for the rapid manufacture of all guns, including the provision of the material and of extra manufacturing plant.

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.