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There is a saying that "every private soldier carries a field marshall's baton in his knapsack". In the same way I believe that the average "man in the street" believes he could have been a second Thomas Edison if only someone had pointed him in the right direction. Therefore any book on invention is likely to be read by a lot of people.

Tom O'Dell's book is certainly about inventions and inventors. But it is much more than that. It is a scholarly work, recording the history of such a complex subject as patent legislation with full research of the relevant documents, which are referenced and carefully included unobtrusively in the text. By the very nature of such a task it could have ended up a very boring book, but the author has so skillfully sprinkled it with stories of the personalities involved, politicians as well as inventors, that it is both enjoyable reading and an accurate chronological account of the subject.

One chapter, for example, is largely concerned with Marconi and the Wright brothers whose inventions are familiar to us all, but whose private lives are less so. Of the Wrights he says: "The two men worked only on their aircraft. There were no wives, no children, no friends even." Whereas of the other inventor he writes: "Marconi seems very different . . . He seemed to be incapable of boarding a transatlantic liner without getting engaged to some young lady once the ship was well under way."

For me, the principal point that emerges is that neither Marconi nor the Wright brothers were concerned about the uses to which their inventions might be put. "Their hope may simply have been to get on with their work, which they were clearly absorbed by, protected from worry about where the funds might come from." How many of us have been down that road? And then: "How many important innovations, important in that our whole environment or way of living may be changed, are brought about by people who just get taken over by their fascination, and complete absorption, in some hardware problem."

Part of the story of most of the inventors themselves is all too familiar, of the best ideas being initially rejected and of the inventors themselves having little financial encouragement. But the author's main story, as the title implies, is about secret patents. He is therefore involved in untangling a very complex web. As he says in his introduction: "The attempt to combine the history of inventions with social, economic and patent law history is undoubtedly an ambitious and difficult task." I think he succeeds.

The whole idea of novelty is at best, a "grey" area. I remember reading, as a teenager, a children's encyclopedia which, describing primitive man, said: "He picks up a stone and throws it - the first game of cricket is being played." I remember thinking what a stretch of the imagination that called for, yet the claim to prior invention in the patent legal system's history is often just as remote.

Later on the author reminds us that "today's patents mean different things to different industries", pointing out that the pharmaceutical industry values them highly, aerospace hardly at all.

Naturally a lot of the legislation about secrets was influenced by inventions that concerned weapons of war, a fact well summarised in the introduction: "Inventions that the state believed should be kept secret must have appeared important at the time . . . What was happening at the time may well have been the reason for the invention in the first place."

What kind of people will want to read this book? Perhaps few in its entirety. But although it will have special appeal to engineers, and especially to electrical engineers such as myself who can fully appreciate the technological content, most of it can be read easily by people without specialist technical knowledge.

It will clearly be of special interest to lawyers, perhaps most of all to "armchair lawyers" who will find much that pleases them. So also will those "of riper years" because they were a part of the history described, of the 1930s when the Defence of the Realm Acts (DORA) was much in the news, because they remember the invention of the cavity magnetron, of radar and, of course, the atomic bomb.

My only regret was that the author did not extend his discussion of the National Research Development Corporation to say how it developed the habit of forming separate companies as soon as it thought it was on to a winner, as was the case with Hovercraft Development Ltd, the Gyreactor Corporation and Tracked Hovercraft Ltd. I was also hoping O'Dell might have thrown some light on the pilotless aircraft ("flying bomb") developed at the RAE in 1922 and capable of more than 400 miles per hour. This was kept so "secret" that only those who knew people who had worked on it knew anything about it. But I guess it was never even patented.

O'Dell's book fills a gap in the whole story of patents.

Eric Laithwaite is an inventor and emeritus professor, Imperial College, London, and visiting professor, University of Sussex.