CAIRO — FOR more than 3,000 years, people have been trying to save the Sphinx. From the pharaohs, Greeks, and Romans to Napoleon and present-day scientists, the preservation process has puzzled, intrigued, and humiliated restorers.
In fact, it is a miracle that the world-renowned half-man, half-lion still sits majestically on the Giza plateau after so much restoration work. It is thinner. The neck, of lighter stone, looks bandaged and distorted. The stones of the figure's hindquarters are patched or falling, and a weather vane sits on its rump.
Laymen might criticize what seem like careless, hasty efforts. But a conference of 70 scientists from many disciplines and countries held in Cairo earlier this month highlighted how complex preserving the 4,600-year-old Sphinx really is.
"The problem is that all conservation work to some extent is still an experiment," says Kent Weeks, an Egyptology professor at the American University in Cairo. "You can run a series of tests. But, until you see what happens over 50, 100 years you can't be sure."
The problems facing the historians, geologists, chemists, artists, environmentalists, and conservation specialists who attended the conference are not unique to the Sphinx.
From temples in Cambodia to Stonehenge in England and Mt. Rushmore in the United States, pollution, population expansion, war, and restoration efforts are damaging mankind's heritage.
No solutions were reached during the Cairo conference, the first multidisciplinary, international meeting of its kind about preservation of the Sphinx. It was agreed that restoration activities begun in 1988 are scientifically sound and should proceed. A committee of scientists will continue to study the Sphinx, while more data are collected.
After three years, solutions should finally emerge, according to Zahi Hawass, the Egyptian Antiquity Organization director general for the area encompassing the Sphinx and the pyramids.
"We need minds. We need expertise, the people who have knowledge," Dr. Hawass says. With a budget of more than $400,000, money is not the problem, he adds.
Despite what seemed like inconclusive results, participants were pleased with the symposium's outcome. "When people get together for the first time to have a full information exchange you can't expect an enormous amount of detailed decisionmaking," says Frank Preusser, scientific director of the J. Paul Getty Conservation Lab in Marina del Rey, Calif. "It remains to be seen if the conference will accelerate the restoration procedures of the Sphinx. There is a great risk that responsible people will respo nd to external pressure, the public and media, and hurry for quick fixes without careful resolutions," Dr. Preusser says.
The problems threatening the Sphinx are innumerable. The monument was hewn from 50 million-year-old limestone rock, some of it strong and some weak. While the head is made of relatively durable rock, the body and shoulders are not, raising concern that the head could fall from the 65.6-foot-high creature.
TEMPERATURE changes, wind erosion, and pollution from cars, tourist buses, and the urban sprawl practically reaching to the feet of the Sphinx increase decay. Underground sewage water and vibrations from nearby quarries, cars, and buses also add to the pharaonic monument's demise. Despite a deterioration rate that has been greater in the last 50 years than in the previous centuries combined, the Sphinx continues to survive.
Since the Old Kingdom when the Egyptian Pharaoh Tuthmosis IV began restoring the monument, 1,000 years after its construction, conservators have fought to preserve the Sphinx.
These efforts continue to the present day, not always with positive results. Two decades ago, a chemical injected into the body to harden the rock soon flaked off, taking some of the invaluable mother rock with it. In the 1980s, workers covered the base of the Sphinx with large stones and cement, which proceeded to eat into the permeable body.
In February 1988, a 300-pound block dropped from the beast's right shoulder. This led to an international outcry, 10 months of debate, and the resignation of the Egyptian antiquities chairman.
In 1989, a new restoration approach began. Sculpted smaller limestone blocks replaced decaying ones. Natural mortar was used instead of cement. The Getty Institute also installed a 6 1/2-foot-tall weather station to measure natural and man-made forces affecting the Sphinx. The data collected show that environmental effects are more serious than previously believed.
While the innumerable problems surrounding the Sphinx's restoration seem unending and unsolvable, other time-honored monuments suffer from the same or more extensive problems.
The Acropolis in Athens, Greece, and the Roman Forum in Italy, both constructed of limestone, suffer decay similar to the Sphinx. The monstrous statue of the Pharaoh Amenhotep III in Luxor, 400 miles south of Cairo, has a huge and expanding crack, largely caused by pollution from the cars and tourist buses that pass constantly on a nearby road.
Meanwhile, over the years conservators try different techniques, start new trends, racing with the clock to save priceless symbols of the past. Cement, believed to be everlasting, has been used all over the world to stabilize ruins. Frequently, however, it accelerates their destruction, Preusser says. A coating similar to clear nail polish was applied to the surface of wall paintings, painted and carved stone, and other painted objects. This soluble nylon created a sealed environment that expedited deter ioration.
"It was like putting fruit in a plastic bag and putting it in the sun," says Dr. Weeks. "Originally we thought the damage was from the outside stone, but the real evil was in the rock itself."
At Egypt's Karnak Temple, Weeks says, a canal built around the site to extract harmful ground water increased water levels.
Restoration is no easy matter. While the general public may scoff at mistakes made, scientists are reluctant to cast blame. "One should always be careful in condemning someone else," says Preusser. "The urgency of conservation often puts pressure on people to do something."