A holograph letter, 1866, from Sam[uel] Ferguson, poet and antiquary, from Dublin, to M. le Capitaine Biol?, referring to prospectuses and subscription papers in connection with the recipient's studies, the Fenian revolt in Ireland (with a quotation relating to Fenian cooking-places from John O'Mahony's translation, 1857, of Geoffrey Keating: Foras Feasa ar Eirinn), and the writer's survey of Tre Caerau [Tre'rceiri] in Caernarvonshire. Endorsed is a full-page sketch or 'Rough Survey of the British Fortress called Tre Caerau' by the writer.