CHIMNEYS.

Thames Star, Volume XVII, Issue 5152, 22 July 1885, Page 3

CHIMNEYS.

A soundlybuilt chimney vibrates, or swings from side to side, as s whole, under sadden and violent shocks of wind, and is in reality safer when it does so than when it stands in sullen and unmoved resistance, The vibration indicates that the several constituent parts of the structure are firmly compacted into coherent, continuous, and, as it were, a homogeneous mass, which can sway from side to side like a steel rod or spring, without any tendency to dissolve its continuity and break asunder at some intermediate point. The absence of vibration, on the other hand, means that there is not this iutegrity of coherence, and that there are, so to speak, fissures of substantial continuity in the structnre, at which disruptive strain is unavoidably developed Sudden shocks of wind bursting upon lofty colums of brick-work in such circumstances tend to break them across at the. joints were the interruption of continuity occurs. The movements of vibration are then absorbed, and converted into the less desirable con* dition of molecular strain.