Edinburgh Castle's famous one o'clock gun celebrates its 150 year this week.
The gun that allowed sailors on the Firth of Forth to reset their chronometers, also was the signal for Greyfriars Bobby to leave the grave of Old Jock Gray and head to John Trail's eaterie for lunch.

Tam McKay alias 'Tam the Gun' who fired the gun for 25 years and died 5 years ago wrote a book about his expereices with tourists at Edinburgh Castle, the book was titled 'What time do they fire the one o' clock Gun?