Description
"These brick retorts are 9 feet long and with diameters of 22 and 13.5 inches, set four in an oven to one unarched furnace. Each retort will, it is affirmed, carbonize 500 tons cannel coal, or 2000 tons per oven of four, without any repairs whatever. Decayed bricks may be removed from these retorts and new ones inserted, and when thoroughly repaired they are again equal to new." — Encyclopedia Britannica, 1893