Some of these banks were doubtless used also by the Romans as roads, not for wheeled vehicles, but for pack horses in connection with the salt industry. The Romans were well acquainted with the manufacture of salt by evaporating sea water in pans or reservoirs prepared for the purpose. The flat coasts of Lincolnshire are especially favourable to this industry. Remains of such pans can still be detected on Bicker Haven, which is many miles from the present sea-shore; but the principal saltworks appear to have been at Wainfleet St. Mary, just outside the Roman Bank. If Ptolemy’s “Salinæ” is to be placed in Lincolnshire, as some suppose, no spot is so likely as Wainfleet. There was an ancient road into the Fen called the Saltway, or Bridge End Causeway, which crossed the Cardyke between Swaton and Bridge End. It is found on both sides of Bicker Haven, which must have been crossed by a ferry, and thence it points north-east through Frampton and Wyberton to Redstone Gowt and the Seabank beyond the Witham. If this be a Roman way—and remains found along its course in Kesteven seem to prove the fact—it probably belonged to the late Roman period, after the seabanks round the Wash had been completed. But the Wainfleet saltworks may have been developed much earlier, and the salt conveyed by road through Lindsey to Horncastle and Lincoln. Oysters were another commodity that could be procured from the Boston Deeps, though they were not of so fine a quality as those from the Richborough beds, which delighted the epicures of Rome.