shaft
The cylindrical section of a column between the base and the capital; also, a tall, continuous portion of a building facade. Photo from 30th Street Station, Philadelphia, Pennsylvania, 2019. 2. A pipe placed on top of a chimney, usually of earthenware, that functions as a continuation of the flue and improves the draft. 3. A distinct, slender, vertical masonry feature engaged in a wall or pier and supporting or feigning to support an arch or a ribbed vault. (Longstreth, 1987, 2000 )