1911 Encyclopædia Britannica/Liner

LINER, or Line of Battle Ship, the name formerly given to a vessel considered large enough to take part in a naval battle. The practice of distinguishing between vessels fit, and those not fit, to “lie in a line of battle,” arose towards the end of the 17th century. In the early 18th century all vessels of 50 guns and upwards were considered fit to lie in a line. After the Seven Years’ War (1756–63) the 50-gun ships were rejected as too small. When the great revolutionary wars broke out the smallest line of battle ship was of 64 guns. These also came to be considered as too small, and later the line of battle-ships began with those of 74 guns. The term is now replaced by “battleship”; “liner” being the colloquial name given to the great passenger ships used on the main lines of sea transport.