places, are described in the margin hereof. (See Plate II. Figs. 1 and 2.) -Care should be taken in placing these bars in the fire-place, so that the air may have free entrance and exit at both ends, by which means they will be kept cooler than solid bars, and will not be subject to be burnt and wasted like them from violent heat. But in case these bars should be placed by accident, or the carelessness or designs of the workmen, so that their ends might be closed with mortar or other substance, I make them with a hole or holes on each side, and at opposite ends, or at the lower edge of each bar, so that the air may be freely admitted into them through these openings. The advantage of making furnace-bars hollow so that the air may have a free passage through them is considerable; for, independent of their being capable by this means of enduring a greater degree of heat than solid ones without injury, they will last longer, will in a great degree prevent the coals from burning to clinkers, and may be afforded for the same and perhaps less cost in the first instance. REFERENCE to the PLATE. Fig. 1, (Plate II.) longitudinal view of a bar twentyfour inches long. a, a hole in the one side, about one inch in diameter; a similar hole is made in the other side at the opposite end. Fig. 2, end view of a hollow bar, with the usual dimensions, one twenty-four inches long. In witness whereof, &c. Specification places, are described in the margin hereof. (See Plate II. Figs. 1 and 2.) Care should be taken in placing these bars in the fire-place, so that the air may bave free entrance and exit at both ends, by which means they will be kept cooler than solid bars, and will not be subject to be burnt and wasted like them from violent heat. But in case these bars should be placed by accident, or the carelessness or designs of the workmen, so that their ends might be closed with mortar or other substance, I make them with a hole or holes on each side, and at opposite ends, or at the lower edge of each bar, so that the air may be freely admitted into them through these openings. The advantage of making furnace-bars hollow so that the air may have a free passage through them is considerable; for, independent of their being capable by this means of enduring a greater degree of heat than solid ones without injury, they will last longer, will in a great degree prevent the coals from burning to clinkers, and may be afforded for the same and perhaps less cost in the first instance. REFERENCE to the PLATE. " Fig. 1, (Plate II.) longitudinal view of a bar twentyfour inches long. a, a hole in the one side, about one inch in diameter; a similar hole is made in the other side at the opposite end. Fig. 2, end view of a hollow bar, with the usual dimensions, one twenty-four inches long. In witness whereof, &c. Specification |