Some years ago, the Alpinist Bill Ruthven went on an expedition to Norway. Asking the distance to base camp, he was told it was about five miles. Only later, after setting out on foot, did he realise that in Scandinavia, a "mile" is 10 km, not 1,760 yards. This is the book that could have saved Ruthven a pair of sore feet.

Both authors have obviously been promising themselves they would write this dictionary for years. Into it they have packed the rules of every sport and game you have heard of, the currency units of every country on the map, the laws and units of all manner of sciences, and the ranks of the armed forces of the United Kingdom and the United States, along with many thousands of other items.

As a result the book is one of the few reference works one might actually sit down and read for pleasure, carried along in just one page from field goals to field marshals to field strengths to Fibonacci series to fifths (both alcoholic and musical).

As well as being exuberant, the book is thorough. The acre-foot is there (for water in reservoirs), and so are the many types of year, each subtly different. From physics, the barn and the Brewster angle are defined, and from history a whole raft of eras and periods.

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However there are some omissions. The ban, Alan Turing's unit of certainty, does not appear. Nor does the "separative work" unit, the measure of uranium enrichment. And although the Georgian era is defined, the antebellum is not. More seriously, the definition of the FTSE Index given by the authors is plain wrong.

Irritating rather than inaccurate is the book's methodological approach. On almost every page there is a little digression on a subject which happens to interest the authors--a law of physics or chemistry, a definition of some bridge term, a chat about the trade winds or an explanation of glissando, for example -- but which has no direct relation to measurement. A lengthy comment on pronouns uses up nearly a whole page for no apparent reason, and elsewhere there is a mini-discourse on the fact that over the years people have been getting taller. And the authors do not know what the word derive means: pro rata does not "derive" from Latin -- it is Latin.

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In other words, if you share the kind of magpie mind of Mike Darton and John Clark, you will probably like The Dent Dictionary of Measurement a lot. But it might well not pass muster on the library buying list, despite its appeal as a present-- for giving or receiving.

To look on the positive side, I can now swot up for conversations with cricket bores by locating in the dictionary the position of backward point or deep midwicket. (The only sport I know that is missing is korfball, unless you count the Eton Wall Game.) I can also talk knowledgeably of cord-feet with lumberjacks, point out a doylt of pigs should I spot one, and bandy verse forms with poets. The list of these is voluminous, extending from the obvious, such as haikus, sonnets and limericks, to virelays, ottava rimas and villanelles.

For all the authors' scholarship, some gaps remain. Take nails, a problem area. Most of us know about the nail as a unit of cloth equal to one-sixteenth of a yard, but what about the measurements of the pointy metal things used to hold pieces of wood together? Here we find details of the British and ex-colonial nail measurements, which go in quarters of an inch, whereas in the United States nails come in penny sizes linked to their cost. And what about nails in the rest of the planet? There are more than a billion people in China--how are they ever going to develop DIY-wise, if even the simplest carpentry falls apart due to a lack of units shared with the West?

Undoubtedly one class of user will find this dictionary a godsend. Quiz players will have their lives rendered permanently easier. For instance, almost every country in the world has a currency in which 100 of one unit adds up to one of another unit--if for no other reason than to make the work of calculation practicable.

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If you are asked to name the places that still have 1,000 subunits, go for Tunisia, Oman, Libya, Bahrein and Chile. (How do people get by in Mauritania, where only five khoums make an ouguiya?) You can also find units in the book which are outdated or simply absurd. Ancient paper sizes, units from the now-dead CGS (Centimetre-Gram-Second) system, and the Fugio cent (the first currency issued in the United States), are all there, ready for that one occasion when you really need to know about them.

And in addition there are the germs of many a bad joke and after-dinner speech. A Fulham, you might like to know, is a loaded die; and the geological history of the United States includes the Clinton stage, dating from over 400 million years ago. Finally, the dictionary will help you avoid faux pas with married friends. You knew about silver and golden anniversaries -- but what about silk and/or fine linen (12 years), coral (35 years), or the very ungreen ivory (14 years) anniversaries?

In sum, the dictionary taught me much. And it reminded me of an odd economic conundrum about Japan. The Japanese unit of currency, the yen, is traditionally supposed to consist of 100 sen. Given that one yen is worth less than one sterling penny, or almost exactly one US cent, what can you get for one sen? Maybe this unit is being kept ready for the day when you can use it to buy a supercomputer.

Martin Ince is deputy editor of The THES.