IN July, 1914, it was determined to have a "test mobilization" of the British fleet. "Mobilization" means, in connection with either the navy or the army, the calling up of reserves and filling up regiments or ships till they have the numbers necessary to complete them for war service. In previous years it was usual to have a series of naval manoeuvres during the summer or autumn, to practise our fleets in working together or to work out strategical problems. This generally entailed a partial mobilization, but in 1914 it was determined to see how the machinery for mobilization would work at full power. On the 19th and 20th July the magnificent naval force formed by the assembly of the first, second, and third fleets, with various flotillas of destroyers and submarines, was inspected at Spithead by King George. After a few days' fleet exercises in the Channel the great armament dispersed, the first fleet going to Portland, the remainder to their home ports to give manoeuvre leave. But in the meanwhile affairs on the Continent became so threatening that it was deemed a wise precaution to keep the first fleet in readiness where it was, and to defer giving leave. On the 27th July Austria declared war against Serbia. Two days later the first fleet steamed out of Portland and disappeared from sight. Where it went we do not know, but in a short time it and all our other fleets were swallowed up in "the fog of war", from which some of their ships have from time to time made dramatic entrances upon the scene of conflict, generally attended with unpleasant consequences to the enemy. Events now moved with the greatest rapidity. Germany declared war on Russia on 1st August, and on the day following her troops violated the neutrality not only of Luxembourg but of Belgium, although she--equally with Great Britain and France--had guaranteed the neutrality of the latter country by a formal treaty. On 3rd August the action of Germany automatically brought France into the war, and on the same day the mobilization of the British fleet was completed at four o'clock in the morning. On the 4th the British ultimatum was dispatched. It was summarily rejected, and by 11 p.m. the two countries were at war.