A brigantine is a two-masted sailing vessel with a fully square-rigged foremast and at least two sails on the main mast: a square topsail and a gaff sail mainsail. The main mast is the second and taller of the two masts.
The steamship Columbia, an example of a late 19th-century auxiliary schooner brig-rigged vessel
A topsail ("tops'l") is a sail set above another sail; on square-rigged vessels further sails may be set above topsails.
USS Constitution sailing under (bow to stern) jibs, topsails, and spanker.
La Recouvrance with both a gaff topsail and two square topsails; the partly obscured sail between the topmasts is a topmast staysail
Image: Sails 19th century ship