History of the Nelson Monument time ball
- 1809 The world famous clockmaking firm Messrs
- 1818 The observatory on the Calton Hill opens officially.
- 1829 Portsmouth experimental time ball set up. Drawing of Portsmouthexperimental time.
- 1833 Time ball set up at Greenwich Observatory. The East India Company decides to set up time balls along its trade routes.
- 1853 Time ball set up on the Nelson Monument, Edinburgh. Ritchies design and supply the electric clock.