primitive old antique stone block foot warmer for horse drawn sleigh or buggy

Early 1900s vintage stone 'brick' foot warmer for buggy or sleigh, about 9 1/2" x 7 1/2" over the block. Much used, stained and worn.

These were once a common sight in town and country alike, but we don't find many of these left around anymore. This one has been left in a barn for about 100 years.