This video from Lonely Planet is a good summary of what makes the clock in Elizabeth Clocktower (aka Big Ben) work. The vide is geared towards kids but adults can enjoy it too.
Jonathan is a consummate Anglophile who launched Anglotopia.net in 2007 to channel his passion for Britain. Londontopia is its sister publication dedicated to everything London.
We don’t currently have any travel plans to London but hope to visit at some point in 2021.