The ancient way of trade, then, ran across the island called afterwards by the Saxons Thorney, the Isle of Bramble, now Westminster. All the trade of the north passed over that little spot, on which arose a considerable town for the reception of the caravans. After resting a night or so at Thorney, the merchants went on their way. Those who travelled south, making for Dover, crossed over the ford, where there was afterwards a ferry. This ferry continued until the erection of Westminster Bridge in the last century: the name still survives in Horseferry Road. After the passage of the ford, the travellers found themselves face to face with a mile of dangerous bog, marsh and swamp, through which they had to plod and plough their way, sinking over their knees, up to the middle, before they emerged upon the higher ground, now called Clapham Rise. To the merchants driving their long chains of slaves and heavily laden packhorses and mules from the north, this was the worst bit of the whole journey. Every day there were rivers to be forded, in which some of their slaves might get drowned or might escape; there were dark woods, in which they might be attacked by hostile tribes; there were hills to climb; but nowhere, in the whole of their journey, was there a piece of country more difficult than this great swamp beyond the Ford of Thorney. They splashed and floundered through it, over ankles, over knees, up to the middle, up to the neck, in mud and muddy water. The packhorses sank deep down with their loads; they took off the loads and laid them on the shoulders of the slaves, who threw them off into the mud, and let them stay there, while they made a mad attempt to escape. Horse and mule; slave and slave-load; iron, lead, and skins: the merchant paid heavy tribute while he crossed the marshes and waded through the shallows of the broad tidal river.