BALTIMORE (AP) _ Using modern technology to unlock ancient secrets, scientists have deciphered five pages of the only known copy of a 2,300-year-old Greek text by the mathematician Archimedes.

The scientists hope to complete a translation of the 174-page treatise, ``On Floating Bodies,'' by next September.

Scholars believe the treatise was copied by a scribe in the 10th century from Archimedes' original Greek scrolls, written in the third century B.C.

It was erased about 200 years later by a monk who reused the parchment for a prayer book, creating a twice-used parchment book known as a ``palimpsest.'' In the 12th century, parchment _ scraped and dried animal skins _ was rare and costly, and Archimedes' works were in less demand.

Two teams of scientists, from Hopkins and the Rochester Institute of Technology, are using digital cameras and processing techniques as well as ultraviolet and infrared filters developed for medicine and space research to reveal the hidden text.

The Hopkins team used ``hyperspectral imaging,'' recovering images of the old Greek text by bombarding it with ultraviolet light, causing the parchment to fluoresce in spots where the vanished 10th-century ink had altered its chemistry.

``This is cutting-edge science for historically and culturally valuable documents,'' said William Christens-Barry, a physicist at the Hopkins School of Medicine.

The manuscript is the only copy in the original Greek of Archimedes' theory of flotation of bodies. The text and diagrams also contain the roots of modern calculus and gravitational theory.

The two teams have been working on the so-called Archimedes Palimpsest since January in a competition to determine who will analyze the rest of the manuscript. A decision will be made by the end of the year.

An anonymous buyer purchased it at a 1998 auction for $2 million, and entrusted it to a Baltimore gallery.