The universal availability of accurate synchronized time is taken for granted in most areas of the world today, but ‘twas not always so. When Big Ben was built in 1859, charts were issued to show the allowance that had to be made for the sound of the bell, traveling at ~768 mph, to reach different parts of London. This one is from 1875:

Bigger version here. The correction at Paddington Station was 6 seconds, 8 seconds in Notting Hill, and 13 seconds at the Royal Greenwich Observatory, itself the seat of a fledgling universal time standard. (via @michalmigurski)