(under the class definition) Devices applied to a stack or smokebox for conducting the smoke and sparks and discharging them upon the ground or into the air. They need not necessarily be conduits but may be shields or deflectors. Includes conduits applied the stack of a boiler used for threshing purposes on a farm, the conduit being carried at a distance from the boiler or engine and discharging into a water receptacle to prevent the sparks setting fire to the straw.
