Fog everywhere. Fog up the river, where it flows among green aits and meadows; fog down the river, where it rolls defiled among the tiers of shipping and the waterside pollutions of a great (and dirty) city. Fog on the Essex marshes, fog on the Kentish heights. Fog creeping into the cabooses of collier-brigs; fog lying out on the yards, and hovering in the rigging of great ships; fog drooping on the gunwales of barges and small boats. Fog in the eyes and throats of ancient Greenwich pensioners, wheezing by the firesides of their wards; fog in the stem and bowl of the afternoon pipe of the wrathful skipper, down in his close cabin; fog cruelly pinching the toes and fingers of his shivering little ’prentice boy on deck. Chance people on the bridges peeping over the parapets into a nether sky of fog, with fog all round them, as if they were up in a balloon, and hanging in the misty clouds.
Charles Dickens, Bleak House Chapter 1
It is foggy. Earlier in the week we had frost, but now it is fog.
There is nothing wrong with a bit of fog when you know that it presages a fair day. Fog is not smog. London used to be famous for its fogs and smogs, known as pea-soupers because they were thick and green like pea soup. But those evaporated, more or less, with the passing of the Clean Air Acts of 1956 and 1968, which effectively regulated the emission of pollutants by introducing restricted areas where only smokeless fuel could be burned.
Not that Cambridge was ever afflicted by fatal smogs, so far as I know, unless we are talking about mental fogs. Those are a daily occurrence. Psycholinguists have noted that the human mind can be afflicted by an intolerance for ambiguity – thus language learners, for instance, can exhibit signs of frustration when told that a form takes on meaning only in relation to a context, or that two forms which in other cases are distinct are in a given case interchangeable. So I can say I just had a coffee (AmE) or I’ve just had a coffee (BrE) but under no circumstances can anyone ever say I’ve had a coffee before the lesson (except, needless to say, in given contexts, such as football punditry).
Sometimes, as a teacher, you can see the fog descending as you speak. And sometimes you can see it lift. There is nothing like a moment of clarity. So too with the fog today. There will come a moment when I look out of the classroom window and realise that the fog has simply vanished, and that it is sunny.