Late in the evening we crossed the harbour to the dockyard, where papa wanted to pay a visit.  A curious steam ferry-boat runs backwards and forwards between Portsmouth and Gosport.  We passed a number of large ships coated with thick plates of iron; but even the thickest cannot withstand the shots sent from some of the guns which have been invented, and all might be destroyed by torpedoes.  We could hardly believe that some of the ships we saw were fit to go to sea.  The most remarkable was the Devastation.  Her free-board--that is, the upper part of her sides-- is only a few feet above the water.  Amidships rises a round structure supporting what is called "a hurricane-deck."  This is the only spot where the officers and men can stand in a sea-way.  At either end is a circular revolving turret containing two thirty-five ton guns, constructed to throw shot of seven hundred pounds.  These guns are worked by means of machinery.