At the West end of the South aisle a small window depicts the patron saint of Felkirk, St Peter, holding two keys in one hand, one of gold and one of silver. It is not known who was responsible for this window being donated or purchased but it was designed and glazed by James Frederick Preedy, a famous and well-known glazier in the late 19^th century. Members of the Preedy Society often call at Felkirk to see this small window and admire his undoubted skill.