In addition to all this, the great English naval depots--Dover, Portsmouth, Portland, and Plymouth--are situated either on the line of blockade or immediately behind it.

Besides, every advance against this line from the north is flanked by Sheerness and Harwich, so that a retreat to the German coast might be barred.

The conditions for the northern line of blockade will be no less favourable when the projected harbour works are finished.

The blockading fleet finds, therefore, a base in the great harbour of Rosyth, while a cruiser squadron might lie in support off the Orkney Isles.

Every attacking fleet from the German north coast will be unhesitatingly attacked on the flank from Rosyth and Sheerness, and cut off from its line of retreat.