London time (1): Clockmakers' Museum

With so many national museums in London, it's important not to forget the joys of smaller, specialist collections. As well as the sometimes amazing objects they contain, the best of them also offer a different perspective on aspects of wider history. One such is the Clockmakers' Museum in the Guildhall, which I visited today.

Unsurprisingly, the clocks and watches in the museum are impressive. The Guild of Clockmakers has been acquiring them since 1814 so this is the oldest dedicated collection in the world, and includes some real gems. One of John Harrison's clocks is here - H5 which finally won the longitude competition, no less. Other pieces are fascinating as much for their decorative as for their functional roles. There are novelties too - I particularly liked the early-nineteenth century self-winding clock which worked by dropping balls of zinc into sulphuric acid; hydrogen gas was produced, lifting and winding the mechanism. Somehow a battery seems so much easier...

Equally fascinating was the history of the clock industry and the Guild itself. Clockmaking has always been about more than mechanical skill alone; thus while the introduction of the pendulum should have heralded a boom, business was badly damaged by the Great Plague of 1665. The industry had already gone through lean times when the English Civil War brought the collapse of London's luxury goods market. London's history, then, is closely meshed with that of the guild.

Practical information: the museum is in the Guildhall, just down from the bookshop. It's open Monday-Saturday, 9.30-4.30, and admission is free.