The main limitation, therefore, of early trade was that it had to be carried on during the summer months alone: allowing for the time taken up by the voyage to and from the port at either end, the foreign trade on which the inland trade depended was of necessity confined to a few weeks.
What does this mean? That the exports had to be brought to the Port by a certain time: they came on the backs of slaves or by pack-horses. The imports had to be carried into the country for sale and distribution as a return journey by the same slaves and pack-horses. The goods were brought from the country down to the quays, which were rough and rude constructions on piles and baulks of timber on either side of the mouth of the Walbrook, and were there exchanged for the imports. The ships discharged one cargo, then took in another, and sailed away. Nothing was left over; there was no overlapping of one year with another; there was no storage of goods over the winter. When the ships were gone and the caravans had started on their journey through the country, there was nothing more to be done at the Port till the next season. London might fall asleep, if there were any London.
In other words, the trade of London at this period was nothing more than an annual Fair held in the months of July and August, frequented by the foreign merchants bringing their imports and carrying off the exports in their vessels, and by the traders, who led their long processions of pack-horses and slaves from the country to the port, arriving at the time when the ships were due; they exchanged what they brought for the goods that came in the ships, and then went away again. Where they spent the winter it is impossible to say. It is, however, quite certain that they came to London in the summer from north, east, south, and west; that they could not come at any other time. These considerations enable us to understand that London was crowded every summer during the few weeks of trade, but that in winter there was no trade, no communication with any other place, and no communication with abroad. Were there no merchants who stored goods and kept them over who lived in London permanently? None. As yet, none.
The place was, in fact, exactly like Sturbridge beside Cambridge. During the annual Fair in summer Sturbridge was a considerable town; trading of all kinds and from all countries crowded to the place; the shops and booths were arranged in streets; these streets were filled with traders and private persons who came from all parts of the country to the Fair. When the Fair was over the traders disappeared, the booths were swept away, the place became a large common, empty and deserted till the next season.