It began with an exit poll no one believed, much as some ignore the first tremors before an earthquake consumes the landscape.

In a tweet, even Nicola Sturgeon voiced "huge" doubt over what was being suggested. Then it began.

Tremors from England at first: the abject collapse of the Liberal Democrats, a surge from Ukip in the north-east. And everywhere the clear signs that Ed Miliband's English campaign had failed. Even before the first Scottish declaration, Labour were being overhauled.

That might have been bad enough for the pretenders to government. But the unbelievable exit poll said the Scottish National Party were on course to sweep up 58 of Scotland's 59 seats. In the first hours, that sounded like a kind of fiction, confusing all the similes. Earthquake? Avalanche? The political world tilted on its axis?

Election nights will give you every cliché in the book where history is concerned. This time, anyone transfixed by a TV in the small hours with a mobile phone to hand was actually watching history being made. There was no precedent for it, no parallel, nothing in the books.

Tweets and retweets in my own timeline began to tell their own story. What became of the great Stop the SNP tactical voting campaign? So who would be Secretary of State for Scotland after this? If David Cameron was back in business, what did his promise of a European referendum portend? It was barely midnight.

Suddenly, long before the declaration, Sir Malcolm Bruce was admitting that Gordon had gone to Alex Salmond. Tom Harris, once MP for Glasgow South, was identifying the cause of his defeat with the immortal words, "Not enough votes, mainly".

Before we had a single Scottish result, a tweet of mine went from daft-sounding to rational in an instant: "No proof yet, but not a thing says that exit poll is wide of the mark". Meanwhile, out in the ether, Labour people were lost in bathetic, convoluted arguments to explain how their failure was all the fault of the SNP. The night had hardly begun and it was all over.

Finally, another tweet of mine: "We're watching Labour in Scotland die before our eyes". Twitter doesn't allow footnotes. I didn't mean to sound surprised. I meant that the spectacle, the sight and sound of it, had alone won its chapter in the history books.

Then they began to fall, like ninepins. "Kilmarnock is annihilation," was my version of a Twitter obituary for Cathy Jamieson's career. "Douglas Alexander destroyed" was the most I could say of a shadow Foreign Secretary. Kilmarnock, Paisley, Falkirk, Glenrothes: huge swings, vast majorities swept away, an entire political tradition eradicated from the landscape.

Twitter is not great for nuance. It copes well, however, with sheer astonishment. The new medium was witness to the destruction of an old way of political life. It is not history's preferred vehicle, but in the early hours it glimpsed history well enough.