Franklin was a prodigious inventor. Among his many creations were the lightning rod, glass armonica (a glass instrument, not to be confused with the metal harmonica), Franklin stove, bifocal glasses and the flexible urinary catheter. Franklin never patented his inventions; in his autobiography he wrote, "... as we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously." -- Wikipedia