In Their Element. A selection of Poems by Seamus Heaney and Derek Mahon. Belfast:  Arts Council, 1977. First edition. Pp, 18.  Illustrated silver card covers (designed by Cathal Caulfield). This copy Signed by Heaney & Mahon over their respective portraits.   A selection of the works of Heaney and Mahon and presented by the Arts Council of Northern Ireland from 23 May to 29 May 1977.