- In geometry, an octadecagon (or octakaidecagon) or 18-gon is an eighteen-sided polygon.
- Bartolomeo Cristofori (Wikipedia)
Bartolomeo Cristofori di Francesco (Italian pronunciation: [bartoloˈmɛːo kriˈstɔːfori di franˈtʃesko]; May 4, 1655 – January 27, 1731) was an Italian maker of musical instruments famous for inventing the piano.
