摘要: A hole has been drilled in the roof of pharaoh Khufu's second boat pit with a drill and airlock system specially designed to exclude the exchange of outside air and the atmosphere inside the pit. Air samples have been obtained fro... 展开 A hole has been drilled in the roof of pharaoh Khufu's second boat pit with a drill and airlock system specially designed to exclude the exchange of outside air and the atmosphere inside the pit. Air samples have been obtained from three height levels inside the pit through an air probe inserted through the airlock. The air has been analyzed by gas chromatography for the chlorofluorocarbons F11, F12, carbon tetrachloride, and methyl chloroform, and for carbon dioxide, methane, carbon monoxide, nitrous oxide and hydrogen. The stability of the wet air samples in stainless steel and aluminum containers is unsatisfactory. The measurements of the air pressure in the pit during sampling as well as the composition of the air show that the boat chamber is not sealed. The present loss rate of the wood in the pit by decay is estimated to be between 200 g and 1000 g per year. The authors find evidence for substantial exchange of carbon between gaseous carbon dioxide and the limestone rock. 收起