大象传媒 Inside Science - The original Six Pip Masterclock at Greenwich Observatory - 大象传媒 Sounds
大象传媒 Inside Science - The original Six Pip Masterclock at Greenwich Observatory - 大象传媒 Sounds
The original Six Pip Masterclock at Greenwich Observatory
Dr Marek Kukula introduces the original Six Pip Masterclock at the Greenwich Observatory.
