The more important of the vast number of subjects treated of in this MS. are mentioned as being: The usual book of invasions; ancient poems; a plan and explanation of the banqueting‐hall of Tara; a copy of _The Battle of Ross na Righ_ in the beginning of the Christian era; a copy of the _Mesca Uladh_, and one of the origin of the Borromean Tribute, and the battle that ensued; a fragment of the battle of Ceannabrat, with the defeat of Mac Con by Oilioll Olium, his flight into, and return from, Scotland with Scottish and British adventurers, his landing in Galway Bay, and the defeat of Art, monarch of Erinn, and slaughter of Olium’s seven sons at the battle of Magh Mucruimhé; a fragment of _Cormac’s Glossary_; another of the wars between the Danes and Irish; a copy of the _Dinnsenchus_; genealogies of Milesian families; and an ample list of the early saints of Erinn, with their pedigrees and affinities, and with copious references to the situation of their churches. The volume belongs to Trinity College, Dublin. Three pages have been selected. The first contains a copy of the poem on the Teach Miodhchuarta of Tara—a poem so ancient that of its date and author no record remains—and of the ground‐plan of the banqueting‐hall by which the poem was illustrated, published by Dr. Petrie in his _History and Antiquities of Tara Hill_. The ground‐plan, which in this copy is nearly square, is divided into five compartments lengthwise, the centre and broadest of which contains the door, a rudely‐drawn figure of a _daul_ or waiter turning a gigantic spit, furnished with a joint of meat, before a fire, the lamps, and a huge double‐handed vase or amphora for the cup‐ bearer to distribute. This great spit, called _Bir Nechin_, or the spit of Nechin, the chief smith of Tara, which in the drawing is half the length of the hall, appears to have been so mechanically contrived as to be able to be coiled up after use; and the instrument is thus described in another MS. belonging to Trinity College, Dublin, quoted by Dr. Petrie: “A stick at each end of it, and its axle was wood, and its wheel was wood, and its body was iron; and there were twice nine wheels on its axle, that it might turn the faster; and there were thirty spits out of it, and thirty hooks and thirty spindles, and it was as rapid as the rapidity of a stream in turning; and thrice nine spits and thrice nine cavities (or pots) and one spit for roasting, and one wing used to set it in motion.”