A still more important question hinges on their geographical distribution. Nothing can be more unsafe than to found any important deductions on what is known on this subject at present. If all those which are described in books and in journals of learned societies were marked on a map, the conclusion would be that the most of them are found on the east coast of Ireland; a dozen or so in Waterford and Wexford; as many in Dublin and Meath, and an equal number in County Down. But this knowledge may merely mean that the east coast, possessing roads and towns, has consequently been more frequented by tourists and antiquaries than the remote or inaccessible west. Among the records, however, of the Ordnance survey, and in the Du Noyer drawings, there are probably sufficient materials for the purpose. Both are deposited in the Library of the Royal Irish Academy at Dublin; but any person who would attempt to use these materials for the purpose of such an investigation, must be not only an enthusiast, but have his whole time at his disposal. The disarray in which they now exist renders them utterly useless to any ordinary student of Irish antiquities. The Irish themselves seem to have only one tradition regarding their dolmens. They call them all "Beds of Diarmid and Graine," and that is the name applied to them in the sheets of the Ordnance Survey. The elopement of Diarmid with Graine, the daughter of Cormac Mac Art, whose date, according to the Four Masters, was A.D. 286, is one of the most celebrated of Irish legends.[256] The story is, that being pursued all over Ireland by Finn, the disappointed suitor, they erected these as places of shelter, or for hiding in. This is, of course, absurd enough; but it shows that, in the opinion of the Irish themselves, they belong to the period which elapsed between the birth of Christ and the conversion of the people to Christianity. There is no hint in any Irish book that any of them were erected before the Christian era, nor anything that would lead us to suppose that any are more modern than the time of St. Columba. The most extensive group of free standing dolmens known to exist in Ireland, is that in or near Glen Columbkille, at the extreme western point of Donegal. No account of these has been published--so far as I know--in any book or journal, and I am indebted for all I know about them to my friend, Mr. Norman Moore, who paid a visit to the spot this autumn to obtain the information I wanted, and it is from his descriptions that the following is abstracted.[257]