The Dogger Bank, off which the Germans were sighted, is a great shoal almost midway between England and Denmark, and extending to within forty miles of the Yorkshire coast. Its length from north to south is about 160 miles, its breadth is 70 miles, and the average depth of water over it varies from ten to twenty fathoms.[4] South of the Dogger is a second and smaller shoal, known as the Well Bank. Still further south are deeps, such as the "Silver Pit," where the depth is as much as forty-five fathoms. The Dogger is the chief fishing ground of the North Sea. During the winter the waters above it are alive with trawlers, all engaged in reaping the rich harvest of the waters. Immense quantities of halibut, soles, turbot, brill, plaice, cod, haddock, and whiting are taken, packed in boxes--to be carried off by fish-cutters to the ports, or stored in ice until the trawler is ready to return home. Somewhere near the Dogger, probably on its north-eastern edge, the Germans were encountered. The naval battle which followed was not the first to be fought near the great shoal. In 1781 an English and a Dutch fleet met in these waters, and struggled fiercely; but the action was undecided, and the Dutch claimed a victory. * * * * * When the _Aurora_ opened fire, Admiral Beatty's squadron, which was not far away, steered in the direction of the gun flashes. Immediately the German scouting cruisers perceived that a British squadron was after them they turned tail and fled to the south-east. Hipper did not wait to discover the strength of his opponents, but took to his heels at once. This seems to show that his real object was to lure the British ships into the position which he had prepared for them, and there engage them on his own terms. There were 120 miles of open sea to be crossed before the mine-fields were reached.