Corn detectives flock to the great who(and how)dunnit of summer

THE FINE weather may have sent thousands of holidaymakers rushing to the coast, but it has also touched off a serious outbreak of crop-circle fever in the cornfields of Wiltshire and Hampshire.

All day, every day, people are trekking out along the tramlines made by tractor wheels to inspect formations in standing wheat; at night they are sitting out on headlands, looking for peculiar lights in the sky.

In every hostelry, rumours of new formations proliferate, and whenever a car pulls in to the side of a road other motorists draw up behind it to see what is happening.

One new formation in a wheatfield at Manor Farm, near Lockeridge in Wiltshire, drew a typical crowd. A complex of interlocking circles several hundred feet across, the shape appeared during Wednesday night. By Thursday lunch- time, there were a dozen vehicles parked at the bottom corner of the field, and a boy holding a makeshift notice in green ink was exacting pounds 1 from every visitor.

When I arrived, a woman was sitting near the centre wielding two L-shaped copper rods. An American seemed impressed rather than annoyed by the fact that his camera had twice refused to work (malfunctioning of electrical and mechanical equipment is common inside new formations).

Andreas Mueller, a researcher from Germany, was taking measurements. On the question of whether the formation was natural or the work of fakers, Mr Mueller remained reserved. "In Germany we've had 22 formations so far this year," he said, "and I'm quite sure that three were man-made, maybe more. In this one, what's surprising is that the corn is laid in several different directions. It wasn't just that somebody walked it down, all one way."

Equally cautious was the indefatigable English researcher Lucy Pringle. "Unless I'm first into a new formation, and see exactly how the crop has gone over, I find it very difficult to tell whether it's real or fake," she said. But already this year she has photographed over 50 formations from the air and investigated 15 on the ground.

In her view, the season has been "a terrifically busy one". It began early, on the night of 19 April, when a double circle appeared in oilseed rape right under the approach to Thruxton airfield, in Hampshire. The next manifestation, a couple of days later, also in oilseed rape, was close to the prehistoric mound of Silbury Hill - a double ring more than 200ft across, with 33 scroll-like bands between the rings.

She likens it to a Beltane wheel - an ancient symbol used at Celtic festivals in May - and points out that, whatever produced it, the hard stalks of oilseed rape are exceedingly difficult to bend into accurate and attractive geometrical patterns.

Ms Pringle readily accepts that skilled fakers are at work, but after 10 years' research she remains convinced that many formations are the product of natural causes, probably the discharge of electro-magnetic energy. "We know that they appear suddenly, in from four to seven seconds, and that they can have powerful effects on people, sometimes beneficial, sometimes harmful."

She is annoyed that in July the BBC set out "to rubbish the whole phenomenon" by showing how easy it is to produce fakes, and hiring practised hoaxers to construct a complex of circles on Milk Hill, near Alton Barnes. "It may look all right on the film," she said. "But as soon as you went into it on the ground, you could see it was a chaotic mess."

Crop Circles: The Theories

IN ORDER of increasing likelihood, there are three principal theories to explain crop circles. The first is extraterrestrial visitors; the second, natural phenomena such as unusual forms of lightning; and the third is humans armed with some string and a plank or garden roller.

Although the UFO idea has excited onlookers since the first formations came to wide public notice in Westbury, Wiltshire, in August 1980, it has never convinced sceptics - generally because any crop circle can be reproduced by people, given time and patience.

The alternative non-human possibility is strange weather. William Levengood, a retired biologist from the University of Michigan, reckons that unstable vortices of ions in the ionosphere descend to the ground and cause a discharge which heats the corn - swelling the nodes on the stems (as is sometimes observed) - as it whirls it round and lays it flat. Nobody has ever observed it, but nature is capable of strange things.

Another weather theory suggests micro-tornadoes, as a cause but this does not explain the huge number of circles, nor the fact that their number has grown and fallen in line with media coverage. The human theory does.

In 1992, a number of teams admitted creating most of the famous hoax formations. The process is simple: all you need is some string, a stick, and something to flatten corn. Instructions are available on the Internet.

CHARLES ARTHUR