A sail is a device used to catch the wind for use to propel a vessel through the water. In Hornblower's time is was typically made of canvas. Sails are fore-and-aft rigged and square rigged. Running before the wind, the square rigged is more efficient, whereas the fore-and-rigged can sail closer to the wind.
Names of SailsEdit
From bottom to top:
The topsail or tops'l. It is sometimes divided into the upper and lower topsail. The top-brim is a space near the centre of the topsail, so named because when the topsail is extended it lies near the top of the lower mast
The topgallant (t'gallant or t'garns'l) is the sail on a mast immediately above the topsail. ant. Some full-rigged ships set two t'gallants, the upper and lower.