“Who knows where the time goes?” sings Sandy Denny in that beautiful song of hers, which is the centrepiece of her own life and work. And who knows where the time goes for all of us? And who knows where that time goes, especially when we find ourselves in really exciting and interesting places?

Anyway, among the interesting, and often exciting, places to be in London are the various museums dealing with clocks and time. I can think of five of them, not all focusing on the same scientific aspects of clocks and time, but all dealing with this fascinating subject. And I would put them as follows.

My five are the Wallace Collection, which has a wonderful collection of fine historical clocks, especially French examples. Then we have the British Museum, with its incredible collections of clocks and watches, going from mechanical clocks to precision watches and chronometers.

And then we come to the place where time itself seems to begin: the Royal Observatory at Greenwich. It gave us, of course, Greenwich Mean Time, and here we have the historic home of the Prime Meridian and the four famous marine timekeepers made by John Harrison, the great pioneer of precision timekeeping at sea. These instruments helped solve one of the great problems of navigation: how to establish longitude accurately.

Then we have two more really interesting museums: the Clockmakers’ Museum, now part of the Science Museum in South Kensington a remarkable collection of historic clocks, watches and chronometers,

And finally, there is the Clockworks Museum at West Norwood, which we visited for the first time yesterday.

This is a very specialist museum, dealing with electrical horology: electric clocks, synchronised timekeeping, and the technology behind public clock networks. We were privileged to be part of a guided tour yesterday, conducted by its curator, Kirsten Tambling, who, in fact, is none other than the daughter of one of my classmates at Dulwich College.

Kirsten gave us the lowdown on these clocks, and she mentioned some really important developments in the history of timekeeping.

The main thing, of course, was that clocks became public, and they had to become synchronised. For the first time, there was a real need to move away from the different local times that had been used in towns and cities throughout Britain. There had to be a single standard time, and the railways were largely responsible for making this necessary.

Before the railways, local time was good enough for most purposes. But once railways had been invented, timetables had to be written out, trains had to leave at particular times, and connections had to be made. You could hardly have every town operating according to a different clock. Railway time therefore became increasingly important, and Greenwich Mean Time eventually became the standard adopted by the railway companies.

Kirsten beautifully explained the various techniques that made all this possible, and, of course, showed us the collection itself. There is also a special laboratory where clocks can be repaired and worked on, which gives the museum an added dimension. These are not simply objects sitting behind glass; they are machines whose workings can still be understood, investigated and, where necessary, restored.

Anyway, we had everything here, from railway clocks to public clocks of the sort one would have seen in town halls and other civic buildings. There were examples showing how clocks in different places could be made to keep the same time, something which we now take entirely for granted.

And then there was one particularly interesting clock, of the sort that one might have seen on that ill-fated liner, the Titanic. It was a reminder that clocks are not just about scientific precision. They are also part of the history of the places in which people lived, worked and travelled, and sometimes of the great tragedies of that history.

We had a great day there, and Kirsten deserves our thanks for such an interesting and informative tour. It is one thing to look at a clock, but quite another to understand the technology behind it and the extraordinary changes it helped bring about.

And, of course, don’t forget that, as far as I am concerned, West Norwood is a delightful part of London in its own right.

Yesterday I finally managed to see St Luke’s, one of the four so-called Waterloo churches. These were built after the Battle of Waterloo, partly to commemorate the victory and partly to provide additional accommodation for London’s growing congregations.

St Luke’s is a beautiful church, with its incredible Corinthian columns at the front. It is one of those buildings that makes you stop and admire it, even if you have come to the area for an entirely different reason. It also has a special connection with one of the cinema’s greatest artists!

You might ask, well, where are the other three?

They are St John’s at Waterloo, St Matthew’s at Brixton and St Mark’s at Kennington.

Five London museums dealing with clocks and time, each in its own way; a wonderful visit to the Clockworks at West Norwood; a fascinating guided tour by Kirsten, with that unexpected personal connection going back to my Dulwich College days; and the discovery of a beautiful Waterloo church.

And all the while, Sandy Denny’s question continues to hang in the air. Who knows?

“Who knows where the time goes?”

Yesterday was a reminder that time is best spent discovering new things, renewing old connections and enjoying the unexpected pleasures that London has to offer. And that, surely, is one of the great joys of being able to explore this extraordinary city.