Theirs is a world of mystery, a place apart. Where children dress like miniature adults, where they speak Pennsylvania Dutch before English (which they usually learn in first grade), where they are entrusted with fieldwork and kitchen duty before they leave elementary school, where they nearly always share three meals a day with their parents and siblings (except lunch during the school year). These are children who grow up without television, computers, or telephones. But they know their grandparents intimately; the boys can harness a horse and take their part in the twice-daily milking operation; the girls can quilt, bake bread from scratch, and look after their preschooler sisters and brothers. What is it like to be an Amish child?           With unforgettable photographs, Jerry Irwin shows moments within the Amish community. Children overlooking the barnraising, "scholars" (as the Amish refer to their elementary-school-aged students) conferring with their teacher, Datt (Pennsylvania Dutch for "Dad") leading a fishing expedition of youngsters, sisters hosing down the buggy, a family at the school picnic, a sister and brother pitching watermelons to Mamm (Pennsylvania Dutch for "Mom"). The photography is immediate, artistic, respectful.           Phyllis Pellman Good provides interpretive text, covering such themes as "Working At Home and Working Away," "Hope Chest Treasures," "Ceremonial Moments," "Belonging," "Visiting," and "Amish Children's Lessons: Driving the Buggy and Lighting the Lamps."