Ordnance Survey Letters Donegal. Letters Containing Information Relative to the Antiquities of the County Donegal Collected During the Progress of the Ordnance Survey in 1835. Edited with an Introduction by Michael Herity. Preface by Brian Friel. Limited Edition of 150 Copies, bound in half calf, marbled boards. Dublin: Four Masters Press, 2000. Pp xxiv, 148. With two fold-out maps in the text. a fine copy. John O'Donovan was employed by Thomas Larcom, Superintendent of the Survey, in the autumn of 1830 to research the ancient forms of place-names with the object of arriving at an approved spelling of each name to be marked on the ordnance maps. He became the leader of a team of Irish scholars recruited by Larcom from that time on: Patrick O'Keefee, Thomas O'Connor and Eugene and Anthony O'Curry. The poet James Clarence Mangan was also a member of the team, which was later captained by George Petrie. The OS Letters, begun in Co. Down, are commentaries written regularly from the field between 1834 and 1843, detailing the progress of John O'Donovan and his fellow workers in ascertaining the forms of the names as pronounced and understood locally, and deciding on the orthography of the nanes to be engraved on the printed maps. While the Field Name Books are the basic document, the Letters, written almost entirely to Thomas Larcom at Mountjoy Barracks in the Phoenix Park, contain much interesting material, explaining the rate of progress O'Donovan and his colleagues were making, and describing the characters they met. Donegal was the fifth county visited by O'Donovan. Brian Friel's play "Translations" set in a small village in Donegal, was inspired by these events.