Franklin Look up Franklin at Dictionary.com
surname attested from late 12c., Middle English Frankeleyn, from Anglo-French fraunclein "a land-owner of free but not noble birth," from Old French franc "free" (see frank (adj.)), with Germanic suffix also found in chamberlain.

The Franklin stove (1787) so called because it was invented by U.S. scientist/politician Benjamin Franklin (1706-1790). In early 19c., lightning rods often were called Franklins.