Amongst the valuable documents which have been collected and printed by Captain Duro, that having for its title "Letter of One who was with the Armada for England, and an Account of the Expedition," is of most lively interest to us, seeing that it presents a graphic picture of the North and North-West of Ireland in 1588, drawn by one who was an actual eye-witness of what he describes. Before proceeding, it may be well to observe that these adventures have already been dealt with by several writers. The _Nineteenth Century_, September, 1885, contained a valuable and interesting paper, entitled "An Episode of the Armada," by the Earl of Ducie. In _Longman's Magazine_ [September, October, and November, 1891] appeared "The Spanish Story of the Armada," by J. A. Froude; and in the Proceedings, Royal Irish Academy, 1893, Professor J. P. O'Reilly contributed a paper, entitled "Remarks on Certain Passages in Captain Cuellar's Narrative." The present paper has been written with the desire to identify some of the places visited by Cuellar while in Connaught and Ulster. His references to these places are, as might have been expected from a foreigner, in many instances obscure; and in order to correctly trace his wanderings, and identify the spots he visited, an intimate acquaintance with the local topography of the district is essential. Sometimes the clue afforded by his narrative is so slender, that anyone unfamiliar with the localities intended might easily miss the meaning, and be led to an entirely wrong conclusion. The present writer has had the valuable assistance of R. Crawford, C.E., late Professor of Engineering, T.C.D., an accomplished Spanish scholar--not merely a translator--who possesses a practical acquaintance with the idioms of the language. By this knowledge, Mr. Crawford has been able to elucidate many obscure passages in the Spanish book, which would otherwise have proved stumbling-blocks in the way of a proper understanding of the author's meaning. Mr. Crawford has made a literal translation of the whole of Cuellar's letter, which forms the second part of this book. A careful perusal of Mr. Crawford's introductory remarks, and of his translation, will well repay the reader, and is, in fact, needful for the proper understanding of the subject-matter of these pages.