But these comparisons have still to be worked out. As an example of the kind of use that may be made of them, and of the light which our poetry may cast, not only upon physical changes, but upon historical facts, I would refer to the passages in Barbour's poem of _The Bruce_ descriptive of the Battle of Bannockburn.[4] I do not contend for the complete historical veracity of the Archdeacon of Aberdeen, though I think he hardly deserves the sweeping and contemptuous condemnation meted out to him by J. R. Green. As he was born only some two years after the battle, as he had travelled a good deal, and as the field of Bannockburn lay across the land-route from the north to the south of Scotland, we may believe him to have made himself personally acquainted with the ground. At least, he could easily obtain information from many who had been themselves actors in the fight. He had no object to gain by drawing on his imagination for the local topography, more especially as his little bits of local description were not in any way required for the glorification of his hero. I think, therefore, that when Barbour describes a piece of ground, we may take his description as a fairly accurate representation of the topography, at least in his own day; and the scene could hardly have changed much in the generation that had passed since the time of Bruce. Now, many persons who have visited the site of the Battle of Bannockburn have felt some difficulty in understanding why the English army did not easily outflank the left wing of the Scots. At present, a wide fertile plain stretches for miles north and south on the east side of the low plateau on which Bruce's forces were drawn up.[5] A small body of the English cavalry did, indeed, make its way across this plain until overtaken and cut to pieces by Randolph. But why was this force so easily dispersed, and why was no more formidable and persistent effort made to turn that left flank? It is very clear that, had the topography been then what it is now, the Battle of Bannockburn must have had a far other ending.