Baroque: fantastic, grotesque, applied to some of the heavily decorated architecture of the eighteenth century.

Barrel-vault: also called Semi-circular or Wagon-headed vault: a continuous arched roof over an oblong space, resting on the side walls.

Barrow: an artificial mound of earth, forming a prehistoric sepulchral monument.

Bar Tracery: See Tracery.

Base: the lower member of any structure; compare Plinth.

Basilica: originally a building erected for business or legal procedure; specifically the large hall of such a building; later, in Christian times, a church that more or less retains the plan of such a hall.

Batter: the upward, inward slope of a wall, affording greater resistance to Thrust (which see).

Battlement: the termination of a Parapet (which see) in a series of indentations, called embrasures, while the intervening solid parts are called merlons.

Bay: each of the principal compartments into which the vaulting of a roof is divided; also used of the space between any two columns of an Arcade (which see) of a Gothic church.

Bay-window: a window of angular plan, that projects from the wall and reaches to the ground. Distinguished from an Oriel window that is supported on a bracket or Corbel (which see) and from a Bow-window which is curved in plan.