Merrill S. Hall III, headmaster at the Calvert School in North Baltimore for the past 20 years, is leaving the job at the end of the 2003-2004 school year.

Hall, 57, said yesterday that he is planning to take a year off and spend time in Maine, where he and his wife own a house on a lake. After that, he said, he might decide to pursue a job as an interim headmaster, which would allow him the opportunity to see other parts of the country.

"You know when it's time to leave," Hall said of his job at Calvert School. "It's something you need to do."

106-year-old school

Hall is the fifth headmaster at the 106-year-old school, which relishes its traditions, including the required handshake and greeting every morning between the headmaster and each student. The school, in the Tuscany-Canterbury neighborhood, has about 400 pupils.

Hall, the longest-tenured headmaster in Baltimore-area private schools, said Calvert School would benefit by having a new headmaster with a new way of looking at things.

Hall came to Baltimore in 1983 and has led the school through a major growth period, including the expansion of the lower school and the addition of a middle school. Calvert, which had pupils in primary through sixth grade, added a seventh-grade class this year. Next year, the school will add an eighth grade.

The new middle school, under construction across Tuscany Road from the main building, is expected to be completed in January.

Hall also oversaw the school's centennial celebration in 1997 and led the Home Instruction Department until last year when it became a separate division, known as Calvert Education Services. The division supplies Calvert School's home instruction materials to more than 17,000 students worldwide each year.

Announced to faculty

Hall announced to the faculty Thursday that he would be leaving and sent a letter home to parents. He said in his letter that the school has experienced tremendous change over the past few years, and that at the end of 2004, the changes will have been accomplished.

Sally Carr, the head of Calvert's lower school, said the faculty was "devastated" when Hall told them he was leaving.

"I can't think of this school without him," she said. "He has had amazing visions for the school."

Robert J. Mathias, president of the board of trustees, said in a letter: "Merrill has guided our school in providing educational opportunities second to none. Calvert students and their families have benefited immensely from the excellent education provided under Merrill's leadership."

Hall came to Baltimore from a private school in Houston and previously had worked at a private school in Metairie, La.

He and his wife, Bronwen, a teacher at Friends School, have two daughters.