I FOUND HAVE THAT most people of my acquaintance have not heard of the Shroud of Turin, or if they have heard of it, believe it to be a pious fraud, of interest only to the gullible. This is strange, because the Shroud surely lays greater claim to being a tangible, material miracle than any other artifact known in the world today. Pope Paul VI has called it "the most important relic in the history of Christianity."

The Shroud is a white, herringboneweave piece of linen, 14 feet 3 inches long and 3 feel 7 inches wide. It is kept in the Cathedral of St. John the Baptist in Turin, Italy, and has been continuously in Turin for exactly 400 years. On its surface, the Shroud bears the sepia imprint of the face and body of a man who was 5 feet 11 inches tall, laid out in the attitude of death. The imprint is sufficiently detailed to show that the man had been crucified. According to tradition, the man was Jesus Christ, and the Shroud is the burial cloth he was wrapped in after being taken down from the cross.

Because it is a material object, the Shroud has appropriately come into itsown in our age of scientific inquiry: most strikingly, with the advent of photography. The Shroud was first photographed in 1898. The photographer, Secondo Pia, found that the negative of his picture contained a positive image. In other words, the Shroud image itself is the equivalen of a photographic negative. The implication of this is that if the Shroud image is a forgery, it was forged, hundreds of years ago, by someone working in negative.This would have been both exceedingly difficult and pointless. An early forger would presumably have wanted to create as realistic an image as possible - not one that would have to await a hitherto unknown scientific discovery for its effect to be realized.

A continuous record of the Shroud exists back to the 1350s, when it came into the possession of Geoffrey de Charny, a Frenchman later killed at the Battle of Poitiers. One of his descendants gave the Shroud to the Italian House of Savoy, and in 1578 it was transferred to Turin where it has remained ever since, technically owned by King Umberto II (exiled in Portugal), but in fact controlled by the Archdiocese of Turin.

Ian Wilson, an English journalist who has spent years studying the Shroud, devotes almost half his book to the great mystery of where the Shroud was before Geoffrey de Charny came into possession of it. It is a fascinating, although at times highly speculative reconstruction, in which the reader is taken on an absorbing tour through Byzantine history, aspects of Arthurian legend, and the initiation rites of the Knights Templars. Robert Wilcox, an American journalist, of necessity covers some of the same terrain, although his book is far more superficial. But he touches on most of the highlights and may be recommended as an introductory guide. In contrast, Wilson's outstanding study must surely be the most complete yet undertaken of the subject.

The most important material in either book deals with the findings that continue to emerge from scientific inquiry. There is no paint on the Shroud, and probably no blood. The linen is consistent with known weaves of the First Century. A pollen test recently conducted by Dr. Max Frei demonstsrated that at some point the Shroud had been in Palestine. The image shows that the crucified man was nailed at the wrist, not the palm, a highly convincing detail, since medical experts have demonstrated that nailing through the palms would not support the body's weight. No Carbon 14 dating test has yet been conducted. This is because, until recent refinements, such a test would have involved the destruction of an unacceptable portion of the Shroud. Now the test could easily be done without loss, and presumably soon will be. Photos of the Shroud have also been studied by the Pasadena Jet Propulsion Laboratory.

The Shroud is rarely displyed to the public. It is normally kept rolled around a velvet staff, wrapped in red silk, and kept in a wooden casket, which is itself housed within an asbestos-clad iron chest. In the 20th century, the Shroud has been publicly displayed in 1931, 1933, and most recently in 1973, when it was shown on European television. In 1969 the Shroud was shown to members of a special scientific commission, which has since continued its investigation.

"However the image was formed," Wilson concludes, "we may well be entranced by the fourteen-foot length of lined in Turin. For if the author's reconstruction is correct, the Shroud has survived first-century persecution of Christians, repeated Edessan floods, an Edessan earthquake, Byzantine iconociasm, Moslem invasion, crusader looting, the destruction of the Knights Templars, not to mention the burning incident that caused the triple holes, the 1532 fire, and serious arson attempt made in 1972. It is ironic that every edifice in which the Shroud was supposedly housed before the fifteenth century has long since vanished through the hazards of time, yet this frail piece of linen has come through almost unscathed.

"Frustratingly, the Shroud has not yet fully proven itself to us - not uncharacteristic of the gospel Jesus, who at certain times seems almost deliberately to have made his presence obscure, as in his post-Resurrection appearance to Mary Magdalen when she mistook him for a gardener, and in his walking, shortly after, as an unrecognized stranger with the two disciples on the road to Emmaus.

"But one cannot help feeling that it has its role to play, and that its hour isimminent."

The Shroud will be shown again later this year, between August 27 and October 8, with a "congress of world experts," and possibly Pope Paul, in attendance. The Carbon 14 dating test may be done at that time.