The painted wooden plaque has a black-painted, cast lead emblem nailed to it. The emblem depicts the backs of four stylized hands, from coat cuffs to knuckles, clustered to create a lozenge- or diamond-shaped unit. The lead casting is hollow, and in high relief. Philadelphia's founder, William Penn, had seen London left a smouldering ruin after the Great Fire of 1666. He wrote that he wished his city would "always be wholesome, and never be burnt." The "Philadelphia Contributionship for the Insurance of Houses from Loss by Fire," founded in 1752 by a group of citizens led by Franklin, is the oldest property insurance company in the United States. A property owner wishing to purchase insurance requested a survey of his property. The survey was done (usually by a house carpenter) and submitted to the company's board. If the property was considered a reasonable risk, the property owner paid a fee (renewed annually) and was given a plaque to be attached to the front, or street, wall of his property. Later fire marks were sometimes painted with the number of the policy that insured the property. This plaque, the first, was cast by John Stow, the founder who later -- in partnership with John Pass -- cast the Liberty Bell.
First fire mark of the fire insurance company Franklin founded