One o'clock

I went up to the West End for a yoga session and walked back the length of Princes St, it was such a lovely day. Three beautiful sunny days in a row? My reaction was "We're going to pay for this" - good grief, I might be becoming Scottish.

I noticed the time ball was elevated on Nelson's monument so knew it must be coming up to 1 pm. Sure enough, it soon slipped down the pole, followed by the sound of the one o'clock gun - almost a second later, I thought. Hmm, what's the speed of sound? About 343 m/s - a fact once known but long forgotten. So I reckon that it must be approx 300 metres (as the craw flies) from Mills Mount Battery at Edinburgh castle to the bus stop outside the Apple store.