Which got me thinking about the famed London fogs. What happened to them? My father described fogs in the fifties so thick that you would lose your way home, wondering around and around for hours without being able to see further than your hand. Even allowing for some exaggeration, we know London is notorious for its fogs. Jack the Ripper would not be the same without the swirling fog, and where would Sherlock Holmes be without the London fog? What of the famous pea-soup fog or pea souper? Or, as it was called in the 19th century, the London Particular? There are so many descriptions of yellow-green fog in literature that I can only puzzle over the current day absence of this natural phenomena.
But far from being a natural phenomenon, the yellow London fog was made up of sulpher compounds resulting from the burning of coal in factories and households. After the Clean Air Act of 1956, which introduced smokeless zones and limited the use of coal particularly for domestic purposes, the pea soupers disappeared.
Which is why my daughter, a couple of generations later, can look out of the window in south east London and fail to recognize the real natural phenomenon called fog.