BBESSCAMER, or BREAST SUMMER, in building, a lintel-beam in the exterior walls, supported by wooden or iron-posts, or by brick or stone pillars, for sustaining the superincumbent part of the wall. Bressumm•rs are used in the construction of shops, where it it necessary to have the window as large as possible, and consequently the pillars as small as possible, in order to give light, and show articles for sale to advantage.
Where breast-summers are used for this purpose, the superineumbent mass should be strengthened by an arch of discharge or otherwise, for, if not so, they will be found of great injury to the building through the shrinkage of the timber. Where this precaution is not attended to. it almost invariably occurs that the brick-work above is fractured in its settlement, and in some eases to a very considerable extent.
Cast-iron beams are occasionally used flu• breast-summers, hut although they have an advantage in not being liable to rot, and are naturally incombustible. yet they are by no means
eligible for the purpose. Cast-iron should never be subjected to cross strain, as, although it may bear a certain weight with safety, the least addition or disturbance will cause it to break. in cases of fire, cast-iron is much less secure than wood, for it soon becomes red-hot, and in this state. upon the slightest contact with water. will snap asunder ; whereas tim bers, if of sufficient scantling. are seldom entirely consumed, usually only charred on their exposed surfaces.
Bressummers were a necessary part in the construction of old timber buildings. where it was requisite to have them not only for binding, the building together, hut for the sup port or evcry floor, and also of the roof. They were likewise placed at the bottom of the as a foundation to the whole structure, and called silts. See SUMMER.