One familiar sight to American forts of the early-to-mid 19th century is the Hot Shot Furnace, here called the Shot Furnace. This contraption, built in 1843, was for heating solid cannonballs until they were cherry-red, at which point they would be extremely carefully delivered to a gun, from whence they would be sent into the wooden planking of an attacking ship. This ship would then cooperate by bursting into an unquenchable inferno.

At least in theory. I've seen no evidence that any American fort ever fired hot shot into an attacking ship, but there are plenty of examples of this technology being used semi-successfully eslewhere. It was obviously a concept in which American fort designers took great stock, because most American which were operating in the 1840's had themselves a Hot Shot Furnace.

Click here to see Fort Macon's Hot Shot Furnace!