Patent for a new and improved spark arrester. This design consists "a direct flue or smoke-stack . . . [which] projects and deflects the sparks or cinders through perforations in a vertical wall of a stack into a dead-air space that surrounds the draft-flue, there causing these sparks . . . to impinge against vertical ribs that subdivide the annular air-space that intervenes between an inner and outer cylindrical wall of the stack, gravity of the accumulating mass of cinders causing their discharge . . . through gates that are opened by the weight of the sparks above them and closed by their own gravity" (lines 15-30).