-"Tell me, Rosina, what does it look like?" the elderly blind woman whispered to the small girl at her side. The woman's sightless eyes were turned upward, toward the strangely marked, glass-enclosed cloth believed by many to have wrapped the body of Christ after his crucifixion.

Outside, under a hot sun, thousands of pilgrims stood 15 abreast between iron guardrails in a line that stretched as far as the eye could see. Singing old religious songs and carrying placards with the names of their parishes, they waited patiently for hours to enter Turin's 14th Century San Giovanni Cathedral where the Holy Shroud of Turin's is on display for the first time in 45 years.

The 14-foot cloth, marked with burns and patches from a 1532 fire, is suspended-over a black marble altar in an illuminated bullet-proof frame. On it is the faded but recognizable back-and-front image of a bearded man who appears to have been crowned with thorns, savagely flagellated, wounded in the side, and crucified.

The debate over the shroud's authenticity will be continued here Oct. 7-8 when the sindonology (from the Greek word "sindon" or sheet) meets to discuss the results of recent studies.

The experts also are expected to attempt to convince Archbishop Anastasio Ballestrero, the keeper of the relic, to allow new sophistaced experiments.

The Shroud is nevertheless widely considered to be Christianity's most important relic.

Since it went on display Aug. 27 to mark the 400th anniversity of its arrival in Turin, over 1.6 million visitors have passed through the austere cathedral to pray, weep or gaze in silence.

By Oct. 8, when the linen cloth with its red-silk backing is once again folded into a silver case kept in a specially constructed 17th Century baroque chapel, more than 3 million people, including over ten thousand criples and invalids, are expected to have seen the shroud.

The shroud has been in Turin since 1578 when the Home of Savou, later the rules of a united Italy, sent it here to enable St. Charles Borromes to make a pilgtimage in thanks for the end of the "black death" plague in Milan. The relic was last exhibit in 1933.

The cloth is thought to have been brought to Europe by crusades in the Middle Ages. The Confraternity of the Holy Shroud in Turin says that earlier records of the shroud's existence can be traced to Constantinople as well as to mention of a linen sheet in the crucifixion and resurrection accounts in the Gospels of both Mark and John.

The property of the Savoy dukes since 1453, the shroud is now owned jointly by exiled King Umberto and the Italian state.

Although it has periodaclly been termed a forgery most researches today have ruled out the possibility of a houx designed by a medical artist.Current doubters are convinced instead that the shroud belongs to a later period and that the image on it is that of a man than Jesus Christ.

Ever since startling 1808 photos revealed that the cloth was really a negative yielding a high-detailed positive potrait, science has gotten increasingly into the act.

Doctors and experts in legal medical have used blowups of these and later photos to determine brushes on the shoulders that could have been caused by a heavy object like a wooden cross, dumbell-shaped wounds that a Roman flagrum or metal-studded whip would have produced and what appear to be bloodstains on the brow and around nail marks in the writes.

A scientific team to investigate the relic includes several U.S. scientists from the Jet Propulsion Laboratary at Pasadena, Calif. Two scientists in the laboraty's image-processing divisions have already visited Turin, taking photos of various of the shroud and subjecting them to computer enchanment along with color spectrum experiments.

According to Donald Lynn, currently a member of the Voyager space probe mission, "if the shroud is a forgery it would be a greater miracle than if it is real."

Experiments done around the turn of the century suggested that pre-putrefaction physiochemical processes from spices used in burial annointments and from ammonia produced by perspiration at the time of death may have created the image.

Another hypothesis advanced by believers is that the image was produced by radiation energy emitted by the body during resurrection. Others have used the shroud to speculated that jesus was not dead but only in a comatose state when he was buried.

At next month's conference requests will be made to Archbishop Ballestrero, the shroud's custodian, for permission to submit the cloth to further examination including X-rays and neutron-activation analysis that could verify if the stains are of human blood.

The carbon-14 dating method has been ruled out because of the amount of cloth needed for the test. But examination of threads from the shroud and a Swiss criminologist's study of pollen and dust found on it both place it in the Middle East at around the time of Christ.

Don Coero Borga of the International Center of Sindonology in Turin says his organization had long been pressing for a showing both "to help preserve the shroud which develops new wrinkles when kept folded, and to stimulate furhter scientific interest."

But with visitors flocking to Turin from far and wide, the interest in the shroud appears assured. "We never expected such a turn-out", says the Rev. Peter Rinaldi, a Salesian priest from Port Chester, N.Y., who is vice president of the New York Holy Shroud Guild.

In fact, for 12 hours every day te cathedral has been jammed, its pews packed with people praying or staring intently through binoculars at the suspended cloth.

Some, like a pony-tailed gril who wept continuously after the two-minute pause allowed before the altar, or the wizened French priest in a broad-brimmed black hat who crossed himself continuously, appeared deeply moved.

Others seemed more concerned with taking snapshots, and one man, carrying a small boy on his shoulders, emerged from the darkened church into the September light only to speak of finding a good restaurant.

But Father Rinaldi believes the faithful comprise the majority of visitors. "To get here at dawn and to wait three to five hours under a broiling sun has nothing to do with curiosity, but is a sign of devotion and of faith," he said.