In sailing, a snow, snaw or snauw is a square-rigged vessel with two masts, complemented by a snow- or trysail-mast stepped immediately abaft (behind) the main mast.
Two views of a naval snow, by Charles Brooking (1759)
The "snow-brig" USS Niagara (center) in 1913
A brig is a type of sailing vessel defined by its rig: two masts which are both square-rigged. Brigs originated in the second half of the 18th century and were a common type of smaller merchant vessel or warship from then until the latter part of the 19th century. In commercial use, they were gradually replaced by fore-and-aft rigged vessels such as schooners, as owners sought to reduce crew costs by having rigs that could be handled by fewer men. In Royal Navy use, brigs were retained for training use when the battle fleets consisted almost entirely of iron-hulled steamships.
The South Shields collier brig Mary, painted by John Scott in 1855, showing two views of the same vessel. A Bentinck boom is fitted to the foot of the fore-course as a labour saving device when tacking.
A small trading brig entering the Bristol Avon, painted by Joseph Walter
The snow brig Niagara
Rimac, a brig built by Brocklebank in Whitehaven in 1834 for trade between Peru and Liverpool