A bar b, [Fig. 2839], is placed in the tuyère hole and supported at the other end at p. The coal is well wetted and packed around and above the bar, which is then pulled out endwise, leaving a blast hole through the coal, as is shown in the end view [Fig. 2840].
Fig. 2841.
[Fig. 2841] represents a patent tuyère of vertical or bottom draft, in which the blast passes through pipe a and circulates around b, finding egress at c into the fire. c is hollow and receives water from the tank f by the pipe d. The steam generated in the nozzle c is conveyed to the tanks by the pipe e.
Fig. 2842.
