Crop circles have spawned a shelf of square books… and here’s another! However, unlike the rest, this well-presented volume is written and published by self-confessed circle-makers and not the familiar troupe of writers, philosophers, photographers and lecturers. Here, then, is the view from inside the circle-making fraternity, a group many long-term cerealogists regard as near-mythical bogeymen.

This Field Guide evolved from simple guidelines, drawn up in 1994 and republished in 2004 as The Beginner’s Guide to Crop Circle-making. These form the basis of chapter 6, which lays bare the principles used to draw up complex geometric designs and, just as importantly, the techniques and equipment used to trample them out in cornfields. To this has been added a tribute chapter to Doug Bower and Dave Chorley, marking their escapades in the late 1970s and early 1980s, which in turn inspired an active community of around 50 circle-makers. Here, too, are interviews with Doug and other circle-makers and a detailed account of the phenomenon and its key players.

Two further chapters tackle the alleged science behind the ‘mysterious’ ways the crops appeared to be folded, bent or crushed down, their ‘weaves’ and other manifestations, and dissects the many theories – often brilliant flights of thought, but nowhere near the reality, the authors say – about how or who (or even what) made the agriglyphs. The outstanding question – why? – is dealt with in chapter 5, which is among the finest waffle I’ve ever read. Oh, it’s deep enough, and erudite, but it won’t convince those who cannot accept these divine designs as made by mere mortals. To them, the merry band of makers are devious hoaxers whose claims cannot be trusted.

Nevertheless, the authors here justify those claims, offering, for the first time publicly, pretty impressive evidence. That is why I think The Field Guide is a valuable document even if it might not be welcome in some quarters. It will make a great present for anyone who thinks they know all about crop circles. The sheer energy, the feuds between believers and makers, the mythologising, and the rivalry between different circle-making teams will be an eye-opener.