MEXICO.- Researchers from the National University (UNAM) will install an apparatus to take x-rays of the Pyramid of the Sun, because they believe it could be "the tomb of a great master".  In the Pyramid of the Sun in Teotihuacan they intend "to seek the hidden chambers" that exist in the interior. "We are going to install an apparatus to take x-rays of the pyramid, to see if a mortuary chamber exists", affirmed Arturo Menchaca Rocha, regular investigator of the Institute of Physics of the Autonomous National University of Mexico.  "The Pyramid of the Sun has been the subject of great interest on the part of archaeologists. Today the reasons for its destruction are unknown, and one of the possibilities that exists is that this monument had been designed to be the tomb of a great master, as examples in other parts of Mexico exist".  Interviewed by t.v. reporter Guillermo Ochoa, Menchaca Rocha said "archaeologists are skeptic to that respect, because no evidence exists that a great master existed, but to answer this question is an important step that is reacheable with the new technology". This question has led to the excavation of three tunnels in the years 1920, 1963 and 1968: "tunnels were constructed to cross the pyramid. But the tunnel that concerns us is a tunnel that existed before the pyramid and passes eight meters underneath the pyramid, and apparently it is believed to be a sacred tunnel, finished almost at the base of the pyramid". The archaeologist also underlined that in the Pyramid of the Moon, studies they have done have led to the discovery of an internal structure. And a few months ago the existence of some burials at the base was reported, "that leads us to think that the Pyramid of the Sun can have some type of burial too".