The history of time-measurement has been used by many great social and economic historians to illustrate and support their theoretical models. It's one of the technologies we know most about: endless monographs have been written about early clocks and scientific instruments, and we've all looked at pictures of Greek clepsydras, Galileo with his pendulum, Harrison with his chronometer, and nineteenth-century factories with their hooters and clock towers. There can't be much to add to that, can there...?

Well, perhaps there is. With a mixture of original research into municipal records from all over Europe and collation of the existing sources on technical history, Dohrn-van Rossum finds that many of our conventional assumptions about time measurement are misleading or just plain wrong (Marx, Lewis Mumford, E.P. Thompson and Jacques Le Goff are the most prominent historians to get rapped over the knuckles, but not the only ones, by any means).

The book focusses on how the new technology of the escapement-controlled mechanical clock spread across Europe from the late 13th century (strangely, we still don't seem to know for sure where it originated or who "invented" it). Dohrn-van Rossum looks at when towns and cities obtained their first public clock, who took the initiative for this, and whom they employed to build it, but also at how the introduction of the clock changed the way people referred to time - when were working hours, markets, times and durations of council meetings, church services, and other public events first referred to by clock time rather than by astronomical or liturgical divisions of the day?

And, by the way, those liturgical times turn out to have been rather oversold - Dohrn-van Possum takes the opportunity to show us that the Rule of St Benedict doesn't in any way force you to invent a clock. As long as you start at about the right time in the early morning, the prescribed activities set the duration for themselves and take you right through to sunset without the need for an external time-reference. The only thing the monks needed was a rough indication of the time to wake up, which could be done by setting a water-clock based alarm.

It's fascinating to see just how fast the new technology spread and how it created a new profession - rather like computers in the 1940s and 50s, people came into it from all sorts of different backgrounds, from academics to artisans. But it's also interesting to be reminded that we didn't go straight from Prime and Vespers to UTC. In particular, finer subdivisions than an hour were of no interest to anyone except astronomers in medieval times, and most clocks didn't start indicating minutes until well into the 18th (or even 19th) century. And every town had its own local time, and there was not even much standardisation of how the hours were counted - as late as the 1780s, Goethe was complaining about the Italian practice of counting from sunset, which made it very difficult to guess what time it would be when you reached the next town, and whether the gates would still be open when you got there.

Another quite basic thing I wasn't aware of is that the sandglass, even though it has the allure of a much older technology, was actually developed at about the same time as the mechanical clock. So the notion of setting the duration of an activity by a measured time interval was just as new as that of setting the starting time by the striking of the clock. (And all those sandglasses in the background of paintings of St Jerome have to be read as leading-edge academic technology, the medieval equivalent of the Apple II on the desk.)

The relationship of European clock-technology to Chinese and Arab science also turns out to be far from straightforward, although Dohrn-van Rossum doesn't go into quite as much detail on this. What's odd is the way that both cultures were a long way ahead of Europe technically in the early middle ages, but seem to have lost all interest in developing time-measurement just about when the mechanical clock appeared in Europe, and even framed ideological and religious objections to the idea of public clocks (Ottoman sultans were happy to accept clocks as gifts from Venetian and Genoese merchants, but kept them in private).

Unfortunately, this otherwise very interesting book is spoilt by a rather rushed translation into English - Dunlap obviously knows what he is doing, and some parts of the translation read very well, but there are still a lot of places where he didn't get round to tidying up his first draft and getting rid of clumsy Germanisms (even really basic things like translating "Kanzel" as "chancel" when it's obvious from the context that it should be the more common meaning, "pulpit"). At times, I really had to think back to what it must have said in German to make any sense of it. ( )