However slight the defences of the Canongate and Holyrood, Edinburgh proper, it could now be seen, was carefully enclosed and bastioned. On the north side, the North Loch, washing the base of the Castle Rock and filling the valley through which the railway now runs, was sufficient protection; but all the rest of the town was bounded in by a wall, called the Flodden Wall. It had been constructed mainly in the panic after the battle of Flodden in 1513 to supersede an older and less perfect circumvallation, but had been much repaired and modified since. It started from the east end of the North Loch and ran thence along Leith Wynd and St. Mary’s Wynd, crossing the High Street at the Nether Bow Port, and so shutting out the Canongate; it then went so far south as to include the whole of the Cowgate and some space of the heights beyond the ravine of the Cowgate; and the west bend of its irregular rectangle, after recrossing this ravine a little beyond the Grassmarket, riveted itself to the Castle Rock, on its most precipitous side, at the head of the High Street. There were several gates in the circuit of the wall besides the Nether Bow Port, the chief being the Cowgate Port, which was also to the east, the Kirk of Field Port (afterwards Potter Row Port) and Greyfriars Port (afterwards Bristo Port), both to the south, and the West Port, just beyond the Grassmarket and the sole inlet from the west. When these gates were closed, Edinburgh could rest within herself, tolerably secure from external attack, and conscious of a reserve of strength in the cannon and garrison of the dominating Castle. Even if the town itself should yield to a siege, the Castle could hold out as a separate affair, impregnable, or almost impregnable, within her own fortifications. Successful assaults on Edinburgh Castle were among the rarest and most memorable accidents of Scottish history. III.—THE EDINBURGH POPULATION IN 1561 Such having been the fabric or shell of Edinburgh in 1561, what was the contained life?