Such a power makes a radical distinction between those classes of vessels and the sailing-ship; for the latter can follow only a limited number of courses when the wind blows, and must remain motionless when it fails.
But while it is wise to observe things that are alike, it is also wise to look for things that differ; for when the imagination is carried away by the detection of points of resemblance,--one of the most pleasing of mental pursuits,--it is apt to be impatient of any divergence in its new-found parallels, and so may overlook or refuse to recognize such.

Thus the galley and the steamship have in common, though unequally developed, the important characteristic mentioned, but in at least two points they differ; and in an appeal to the history of the galley for lessons as to fighting steamships, the differences as well as the likeness must be kept steadily in view, or false deductions may be made.

The motive power of the galley when in use necessarily and rapidly declined, because human strength could not long maintain such exhausting efforts, and consequently tactical movements could continue but for a limited time;[1] and again, during the galley period offensive weapons were not only of short range, but were almost wholly confined to hand-to-hand encounter.

These two conditions led almost necessarily to a rush upon each other, not, however, without some dexterous attempts to turn or double on the enemy, followed by a hand-to-hand _melee_.

In such a rush and such a _melee_ a great consensus of respectable, even eminent, naval opinion of the present day finds the necessary outcome of modern naval weapons,--a kind of Donnybrook Fair, in which, as the history of _melees_ shows, it will be hard to know friend from foe.