Thirdly, the substitution of steam for sails has very largely reduced the enduring mobility of the commerce-destroying warship. In time of war no warship will ever go further from the nearest available supply of coal than is represented by considerably less than half of the distance that she can steam at full speed with her bunkers full. If she does so she runs the risk, if chased, of burning her last pound of coal before she has reached shelter. Coaling at sea is only possible in exceptional circumstances, and is in any case a very tedious operation. A warship which attempts it will be taken at a great disadvantage if an enemy catches her in the process. Colliers, moreover, are exposed to capture while proceeding to the appointed rendezvous, and if they fail to reach it the warship awaiting them will be placed in extreme danger. All these difficulties and dangers may be surmounted once and again, but they must needs put a tremendous handicap in the long run on the commerce-destroying efforts of a belligerent who is not superior to his adversary at sea. Of course if he is superior at sea the enemy's commerce will be at his mercy, and nothing can prevent its destruction or at least its total suppression. But that is not the hypothesis we are considering. Fourthly, the power of the modern warship to send her prizes into court for adjudication, or to destroy them off-hand on capture is much more limited than was that of her sailing predecessor. If she sends them into port she must either put a prize crew on board or escort them herself. In the former case the prizes, and in the latter case both prizes and their captors are liable to recapture, a liability which becomes the greater in proportion as the enemy is superior at sea. As to the former alternative, moreover, the crew of a modern man-of-war is highly specialized, and in particular its engine-room complement, which must furnish a portion of every prize crew, is at the outset no greater than is required for the full fighting efficiency of the ship. It is probable, therefore, that the captor would in nearly all cases adopt the alternative of destroying his prizes at sea. In that case there will be no prize money for any one concerned, but that is perhaps a minor consideration. A far more important consideration is that before destroying the prize the captor must take its crew on board and provide food and accommodation for them. Any other course would be sheer piracy and would inevitably lead to drastic reprisals. Now, before the captor had destroyed many prizes in this fashion--especially if even one of them happened to be a passenger steamer well filled with passengers--she would find herself gravely embarrassed by the number of her prisoners, and the need of providing for them even in the roughest fashion. A captain having to fight his ship even with a few hundreds of prisoners on board would be in no very enviable position.