AUSTIN, Texas (AP) _ The grandson of a former University of Texas football coach has been charged with stealing a missing page of Albert Einstein's notes from a locked display case at the school, police said.

Samuel K. Royal, 18, was arrested Wednesday evening at his Austin apartment, said Ronald Thomas, a university police lieutenant.

The page of handwritten notes, owned by the university, was reported missing last week from a locked glass case on the fourth floor of the Peter T. Flawn Academic Center. It was among six pages on display from a series addressing the mathematical concept of Euclidean rotation.

Investigators said a telephoned tip led them to the younger Royal's apartment Tuesday where the page was found in a photo album, along with photographs of his grandfather, Darrell Royal, the University of Texas' football coach from 1957 through 1976.

Samuel Royal is not a university student. His father, Mack Davis, is a custodian on the same floor of the academic center where the display case was located.

According to a court affidavit, a woman named Alissa Chambers, who also lives at the apartment where the page was discovered, said Samuel Royal ''walked in and flashed some papers in front of my face and said, 'These are the writings of Albert Einstein.'''

Police could not immediately offer an explanation for the theft. The display case was locked and the glass unbroken when the document was discovered missing.

The missing page is part of an archive of 60 or 70 pages ''upon which Einstein wrote the notes representing his thinking as he was trying to work out his theories near the end of his life,'' said John Chalmers, librarian for UT's Harry Ransom Humanities Research Center.

The university has owned the papers for 25 years. Einstein apparently wrote the notes several years before he died in 1955.

Although the page likely could have been sold for a couple of thousand dollars, Chalmers said, its value far exceeds that amount.

''For all of us, it's a piece of our heritage, and it is not to be replaced. In that sense, it has no price,'' Chalmers said.

Darrell Royal, who is special assistant to the president of the university, did not return a telephone call to his Austin residence on Wednesday.