One with water fed on to the wheel at mid-height, falling and passing beneath. Compare overshot, pitchback and undershot.
Bressumer
(lit. breast-beam): Big horizontal beam supporting the wall above, especially a jetty or projecting storey.
Bretasche
(lit. battlement): Defensive wooden gallery on a wall.
Brise-soleil
(French, lit. sun break): A screen of projecting fins or slats which deflect direct sunlight from windows.
Broach spire
A spire starting from a square base, then carried into an octagonal section by means of triangular faces.
Broch
(Scots): Circular tower-like structure, open in the middle, the double wall of dry-stone masonry linked by slabs forming internal galleries at varying levels; found in west and north Scotland and mostly dating from between 100 B.C. and A.D. 100.
Broken pediment
A pediment with its apex omitted.
Bronze Age
The period from c. 2000 B.C. to 800-600 B.C., characterized by the use of bronze or copper tools or weapons.
Brutalism
City of London
A tendency within Modernist architecture of the later 1950s to 1970s marked by the display of rough or unfinished concrete, large massive forms, and abrupt juxtapositions.
Bucranium (plural: bucrania)
Ox skull used decoratively in friezes on classical buildings, especially those of the Doric order.