Heirs to Ancient Air
Giovanni Battista Belzoni was not known for his light touch. He etched a space for himself in the annals of archaeology by being one of the first Westerners to begin excavating and collecting artifacts in Egypt. But he was more a heavy-handed plunderer than a scholar, and the scars of his work still mar the tombs of several pharoahs.
From such inauspicious beginnings, archaeology has evolved over the last century and a half into a rigorous science. And at the cutting edge, a project currently under way in Egypt is using a high-tech nondestructive approach to probe an ancient chamber.
Borrowing equipment from moon missions and nuclear power plants, the members of this project are seeking to probe a sealed pit that lies at the foot of the Great Pyramid of Khufu, known in the West by the Greek name Cheops. In 1954, archaeologists discovered this chamber and an identical neighbor, both of which were hewn from the limestone bedrock and capped with limestone blocks.
When they opened the first chamber, they found a dissasembled wooden boat in near-perfect condition. The ancient Egyptian workers had sealed off the chamber with a gypsum mortar that protected the wood from water, oxygen and bacteria--the principal elements of decay.
The other chamber of Cheops was left unopened.
Until this year, that is. In October, scientists finally plan to open the second chamber. However, instead of searching for a second boat, these scientists are primarily interested in finding another artifact preserved by the chamber-- ancient Egyptian air.
The goal of the present project is to retrieve samples of the atmosphere from inside the chamber and at the same time avoid contaminating the chamber with anything from the outside world, says Zahi Hawass, who is working for the Egyptian Antiquities Organization, co-sponsor of the project with the National Geographic Society. "Once this atmosphere is analyzed,' says Hawass, "its composition can be simulated in the museum environment to protect organic antiquities like wood [or] textiles, maybe mummies.'
Organic decay is a central concern for archaeologists, who not only find artifacts but also seek to preserve them for future study. Scientists do not yet fully understand what qualities protected these ancient materials through the centuries, and museums often lack sufficient funds to adequately control the environment of displays and storage rooms. For these reasons, many organic artifacts begin to decay rapidly once they are removed from their resting spots. Indeed, the wooden boat, which was assembled and put on display in 1982, has started to show signs of deterioration. Several observers have noted with irony that while this boat survived more than 4,000 years, it is in danger of disintegrating within a few decades.
Aside from archaeologists, this project has also captured the interest of atmospheric scientists, because it offers them the almost unprecedented opportunity to analyze the atmosphere as it was 4,600 years ago--a time long before humans began to significantly alter the atmosphere by burning fossil fuels and deforesting lands. Measuring the concentrations of carbon dioxide, methane, chlorofluorocarbons and other trace gases in this ancient air will help scientists distinguish the natural cycles of the atmosphere from the possibly harmful effects generated by humans.
While bubbles in icecaps have yielded older samples of the atmosphere (SN: 9/29/84, p.205), they have been "minute amounts,' says Lester Machta, director of the U.S. National Oceanic and Atmospheric Administration's Air Resources Laboratory in Silver Spring, Md. "Here we can get liters of air and more, so we can do a lot more scientific analyses.'
The project plan is to drill a hole 3 1/2 inches in diameter through one of the 14-ton limestone blocks that roof the pit. The researchers will …