The Fall of Rome by Martha Southgate.    Evocative but disappointingly inert, Southgate’s second outing (after Another Way to Dance, 1996) depicts the conflicting tensions of experience and expectations that confront African-American males in traditionally white schools.  The carefully organized tale has three protagonists, each representing different points of view as they negotiate the minefield of race relations at Chelsea, a Connecticut boarding school for boys. Each has a reason for being at Chelsea, whose headmaster is eager to have a more diverse student body (a rich alumnus has offered a big gift if minority enrollment increases). African-American.