Ventilating Chimney.

Patent for a new and improved ventilating chimney. This design consists in "the combination, with the smoke-flue, of the ventilating-flue, the thimble provided with outwardly-projecting lugs and inwardly-projecting apertured lugs, the plate provided with a central aperture and with a flange having notches, and the screws passed through the plate into the apertured lugs" (lines 16-23)