It is evident, then, that an ample domain of research is here opened out to the student. In a general sense, every kind of historical document may be available for the purposes of the inquiry. England fortunately possesses in Domesday Book the results of a minute examination of the greater part of the country in the latter half of the eleventh century. For other portions of our islands much information may be gleaned in quarters that might be thought the most unlikely. Besides the narratives of the old Chronicles, which might be expected to contain at least occasional incidental reference to physical features, Charters and other legal documents, in dealing with the holding and transference of land, not infrequently throw light on the former aspect of the ground with which they are connected. The Cartularies of some of our ancient abbeys, besides affording glimpses into the inner life of these establishments, which do not seem to have been always abodes of peace and studious retirement, give indications of the former areas of forest, woods and mosses, or the positions of lakes now reduced in size or effaced. Old Acts of Parliament, looked at from our present point of view, are by no means always repulsive reading. They have one great advantage over their modern representatives in that they are often commendably brief; and in their occasional quaint local colouring, they afford material for interesting comparison with existing topography. Among historical documents I include poems of all kinds and ages. Our earliest English literature is poetical; and from the days of Caedmon down to our own time, the typical characters of landscape have found reflection in our national poetry. It is not merely from what are called descriptive poems that information of the kind required is to be gathered. The wild border-ballad, full of the rough warfare of the time, has a background of bare moorland, treacherous moss-hags, and desolate hills, which can be compared with the aspect of the same region to-day. The gentler lyrics of a later time take their local colouring from the glades and dells, the burns and pastures where their scenes are laid. In the stately cadence of the _Faery Queen_, among the visionary splendours of another world, the rivers of England and Ireland are pictured, each with its characters touched off as they appeared in the days of Elizabeth. And in Drayton's quaint, but somewhat tiresome _Polyolbion_, abundant material is supplied for a comparison between the topography of England at the beginning of the seventeenth century and that of our own time.[3]