But what catches my eye is the announcement that this is the final volume. How could such a distinguished historian pack up without trying to bring the Eighties and the Birt-Hussey era into perspective?
The first time I telephoned Lord Briggs's Sussex home, he was absent on a sad mission - clearing out his London office at the BBC. It turns out that the market-obsessed corporation wound up its small history unit two years ago, and with the book's publication the final link is broken.
I caught up with him yesterday and he explained ruefully that the BBC had no plans for the history to be continued. The next phase of research cannot go ahead because the archives required have not been catalogued. He thinks this has happened because of the huge financial pressure the BBC has been under, rather than any attempt to stop the story being properly told. He adds: "They need a definite archive policy. Unless they get it right, they will lose the richest archive of any broadcaster worldwide." He says there are major programme gaps anyway: in the period he has just covered, for example, early editions of Juke Box Jury, in which the BBC grappled with the onset of Sixties rock culture, have been lost or destroyed.
Lord Briggs, however, does intend to write a new condensed history of the BBC as a private project, and this one will carry the story into the Eighties, with an epilogue about the extraordinary changes during the chairmanship of Marmaduke Hussey. "I know an enormous amount about the present BBC," the historian confides.
The unusual thing about Mr Hussey, from a historical point of view, is that he is the only BBC chairman to have been appointed for two terms - 10 years in all. But 1996, when he finally steps down, draws ever closer, and there is no sign of a chairman-in-waiting on the board of governors. It had been predicted that Sir David Scholey, the distinguished merchant banker appointed as a governor last year, might prove just the ticket. But he resigned abruptly last month to return to the troubled SG Warburg bank. Lord Briggs observes (again from a historical perspective) that there have been some very strange choices of chairman, and that the rumour mill usually gets it wrong. Mr Hussey's retirement will also coincide with the departure of Sir George Russell, chairman of the Independent Television Commission. But will the two jobs be in the gift of a Labour or a Conservative government?
To lunch in Kensington Park Road with Alan Yentob, the approachable controller of BBC1 - a man who likes to throw away his briefing notes and ramble on lovingly about programmes. The wine bar, overseen by a proprietor who buzzes around on roller blades, is within sight of Yentob's five-storey Notting Hill home. This is currently being redesigned to reflect the fact that he is now the father of two small children. Meanwhile, his partner is scouring Wiltshire for a country cottage, a development which makes the metropolitan and cultivated Yentob feel distinctly uneasy. He mentions that Sir Richard Rogers, his very good friend, is visiting the house that afternoon, just to check whether the alterations, including a huge top- floor parents' zone, pass muster. It strikes me that Yentob is one of the few people lucky and well-heeled enough to lead the fulfilled city life advocated by Sir Richard in his recent Reith lectures - he likes to stop off for breakfast, continental style, at a local caf. When people write profiles of Yentob, they often stress his alleged indecisiveness. This was not in evidence during lunch: he ordered a sorbet, then declined to eat it. "Too sweet," he hissed as the waitress cleared the plates. Substitute a substandard programme for that sorbet, and I suddenly realised how tough he could be.
Standing on a railway platform, I'm asked if I'd like to sample the new miniature Mars bars, downsized for the Nineties. They are quite pleasant, the size of an ordinary chocolate, and send me chewing on to the train with a smile on my face. Andrew Byrd, deputy managing director of the ad agency DMB&B which promotes them, says they have been devised as "a more femine eat": too little to harm you. Apparently, Mars discovered that women do all sorts of funny things with Mars bars (no, not just the Marianne Faithfull sort of thing), such as cutting them up into tiny slivers, or rationing themselves to half a bar because Mars is too wickedly fattening. As a child, we had a party game (perhaps it has died out - my children don't play it) in which you had to dress up in hat, scarf and gloves and try to hack off as large a slice of a Mars bar as possible before the music started. Which brings me to the one drawback of the miniatures. The point about the original Mars bar is that it has a very thick coating of chocolate which requires you to really sink in your teeth. There was none of that satisfying physicality about eating the miniature: it had distinct overtones of a Milky Way. But in an age which has reinvented chocolate bars as ice-cream treats, perhaps this is just one more Nineties example of a brand becoming more things to more people.
I spent Sunday in Kent, observing one of the more astonishing natural sights of my life. My sister and her husband have bought a field containing three large muddy ponds, which lie largely undisturbed, bar anglers and a few pairs of coots, Canada geese and ducks. At one reedy margin we spotted a frog, and then another and another. One entire stretch was completely taken over by copulating frogs, mixed up with some equally ardent toads. They were so overcome by passion that you could pick them up without resistance. We were suddenly aware that an entire stretch of reeds was gently croaking: was it ecstasy, or a warning that humans were about? We spent a voyeuristic hour just watching. On our return to London, we found a completely squashed frog in the road. The city is no place for a frog to go a-wooing.