 His well-known memoir on glacial geology written in collaboration with Edmund J. Garwood belongs to this period.Gregory's polar and glaciological work led to his brief selection and service in 1900-1 as director of the civilian scientific staff of the Discovery Expedition.The expedition was in planning during this period, and had not yet set sail for Antarctica when Gregory was compelled to resign from his position upon learning that he was outranked by the expedition's commander, Robert Falcon Scott.