Image: USS Monitor - Wikipedia
"Most people are aware of the curious struggle which arose during
the Federal war between the guns and armor of iron-plated ships.
The result was the entire reconstruction of the navy of both the
continents; as the one grew heavier, the other became thicker
in proportion. The Merrimac, the Monitor, the Tennessee, the
Weehawken discharged enormous projectiles themselves, after
having been armor-clad against the projectiles of others. In fact
they did to others that which they would not they should do to them--
that grand principle of immortality upon which rests the whole art
Now if Barbicane was a great founder of shot, Nicholl was a
great forger of plates; the one cast night and day at Baltimore,
the other forged day and night at Philadelphia. As soon as ever
Barbicane invented a new shot, Nicholl invented a new plate;
each followed a current of ideas essentially opposed to the other."
Source: From the Earth to the Moon - The Literature Network