That the advance of the German fleet had been well planned was indicated by the very fact that it could successfully elude the British cruisers patrolling the entrance to the mine fields that guarded Heligoland itself. Could a British fleet of any size have got between the German high sea fleet and Heligoland the menace of the German fleet would have ended for all time. At the moment, however, the British warships were scattered over the North Sea in such a manner as to preclude such an attempt; and the best Admiral Beatty and Admiral Jellicoe could hope for was to come up with the German fleet and give battle, preventing, if possible, the escape of any units of the fleet to other parts of the sea and to drive all that the British could not sink back to Heligoland. The German dash of one hundred miles across the North Sea was a bold venture and one that the British had not believed the Germans would attempt at that time. British vigilance had been lax or the German fleet could never have gone so far from its base without discovery; and this laxity proved costly for the British; and might even have proven more costly still. Above the German fleet came a fleet of aircraft, augmented to a great degree by three powerful Zeppelin balloons. Lying low upon the water also was a fleet of German submarines. As the German fleet approached Jutland on the night of May 31, it was shrouded in darkness. The night was very black and a heavy fog hung over the sea. The night could not have been better for the attempt, which would, in all probability have succeeded, had it not been for the fact that the British had been forewarned. Forewarned is forearmed; and this fact alone prevented the Germans from carrying out their designs. It is history that the approach of the German fleet had been reported to the commander of the British cruiser _Glasgow_ by an aviator, who had sailed across the dark sea in a hydroplane. Whether the Germans knew that there were but three British vessels in the Skagerak cannot be told, but certainly they believed they were in sufficient strength to force a passage, particularly by a surprise attack, which they believed the present venture would be. Therefore, it must have been a great disappointment to the German admiral when a single big gun boomed in the distance. This was the voice of the British battleship _Queen Mary,_ which, taking directions from the _Glasgow's_ aviator, had fired the opening shot, telling the Germans that their approach had been discovered and that the passage of the Skagerak would be contested. Immediately the German fleet slowed down; for the German admiral had no means of knowing the strength of the British fleet at that point. Hurried orders flashed back and forth. A few moments later three aeroplanes, which had been hanging low above the German fleet, dashed forward. They had been ordered forth to ascertain the strength of the British.