Some time in June I was visiting a friend in north London’s Whittington Hospital on Highgate Hill. As I turned to go in, I glanced at the old Board School building opposite, also called the Whittington. My glance was absent-minded, because I was thinking of my friend, but it couldn’t be casual. Forty years ago, inside that building, I’d had too many remarkable experiences ever to look at it without a small storm starting up in my memory. I’d taught - or tried to teach - there. It was the annexe of a school at the bottom of the hill that in Roaring Boys, a book I wrote about it, I called Stonehill Street.

On top of the school wall there was now a large, and astounding, painted notice (see box): It seemed like an immense joke, but plainly wasn’t. It was in no one’s obvious interest to mock up a joke of that size. The notice must mean what it said. That this instantly recognisable item of social history, this sturdy, characteristically lofty and darkly glowering building, of a style that states its purpose - “I am a school for those at the bottom of the heap” - as unmistakeably as any style of building ever has, had now been bewitched into being an apartment block for those at the top of the heap. The means of bewitchment included the use of Antiques Roadshow language: as in the phrase, fit to be rolled round a connoisseur’s tongue “a fine late-Victorian school”.

Of course there was much that was fine about those educational fortresses. They were built to endure: about their construction there was nothing remotely slap dash or trumpery or indifferent. When I revisited the school at the bottom of the hill a few years ago, I was struck by a gracefully powerful web of beams that supported (or perhaps pretended to support) the ceiling of a room I’d once known very well. It had been used as the art room, and I’d been appointed to teach in it largely on the grounds that my hair was longer than was then usual. (“I can see you’re an artistic chap,” said the head.) My adventures in that and other rooms had not led to detached admiration of ceilings. I was more aware of the dispiriting sour creams and bathroom greens of the classroom walls, and the morose brown of the tiling.

Well, how very odd it all was, I thought. How self-satirising! And I was (I found, as I turned into the hospital) rather bitterly amused by that stress on the “double-height” of the apartments. The cavernousness of those classrooms, the loftiness of those windows (which, if the sun was shining, could plunge half a school into sleep, teachers included), now offered as inducements to take up residence, had been features for which I’d felt a particular aversion.

And now someone has sent me a brochure for this old school transmogrified. No more ordinary word will do for what has happened to it. In the first place, it has a new name: it is now (maintaining daintily the connection with that uncouth past whilst keeping it at arm’s length!) The Academy. (Perhaps, elsewhere, some fine late-Victorian jail will be given the treatment and will become The Oubliette.) The brochure concedes that it was completed in 1880 as a school, but implies that a discerning eye would have spotted, even then, that it was only biding its time: a more appropriate fate awaited it. “It has always displayed,” it astonishingly asserts, “the imposing elegance of a country manor.”

Again, I’m not sure what to do about that - plainly not offered as a joke. I deal with it, in the end, by imagining myself on playground duty, and being (by some error an experienced teacher should have avoided) elbow to elbow with the most difficult boy of my time, Haggis.

“Haggis,” I’d have said. “Help me out. Standing back a little, and detaching yourself as best you can, do you not conclude that this building displays the imposing elegance of a country manor?” I should then have run for it.

And such images, in the brochure, of luxurious, tip-toeing rooms (“designed to preserve - and emphasise - the building’s inherent beauty”), occupying that space that, for l00 years, roared!

And, where so many nervous bunches of keys were carried, and sometimes in my day entrusted to boys of improbable integrity, such utter security, now, video-controlled or voice-controlled: everywhere, five-lever mortice locks! Even Haggis, who laughed at keys, would have been halted in his coarse tracks.

I guess I shouldn’t care about it. All over London, buildings designed for honest purposes are being dandified, what was most down-to-earth and even surly about them are now breathily commended for their architectural dash.

Yet the fate of this building (and presumably of others to follow) that bears the entwined initials of the School Board of London (displayed in the brochure as a kind of chic logo) makes me horribly sad. And that, I think, is exactly because the purring vocabulary that turns to absurd gentility every aspect of a building that was earnestly created and earnestly used, is so patronising.

I fancy that when I say I resent that, Haggis stands shoulder-to-shoulder with me. It’s such a real piece of our history to convert into affluent fantasy!

Sherlock Holmes would have been taken very badly aback. It was just after they’d passed through Clapham Junction on their way to solve the mystery of the stolen naval treaty that he drew Watson’s attention to “those big isolated clumps of building rising up above the slates, like brick islands in a lead-coloured sea.”

“Ah yes,” said Watson, “the Board Schools.” To which Holmes replied: “Lighthouses, my boy! Beacons of the future! Capsules, with hundreds of bright little seeds in each, out of which will spring the wiser, better England of the future.”