RUNCORN has not a vestige to show of Ethelfleda's borough; but local historians have preserved some rather vague accounts of a promontory fort which once existed at the point where the London and North-Western Railway bridge enters the river. A rocky headland formerly projected here into the Mersey, narrowing its course to 400 yards at high water; a ditch with a circular curve cut off this headland from the shore. This ditch, from 12 to 16 feet wide, with an inner bank 6 or 7 feet high, could still be traced in the early part of the 19th century. Eighteen feet of the headland were cut off when the Duke of Bridgewater made his canal in 1773, and the ditch was obliterated when the railway bridge was built. From the measurements which have been preserved, the area of this fort must have been very small, not exceeding 3 acres at the outside;[90] and it is unlikely that it represented Ethelfleda's borough, as the church, which was of pre-Conquest foundation, stood outside its bounds, and we should certainly have expected to find it within. As the Norman earls of Chester established a ferry at Runcorn in the 12th century, and as a castle at Runcorn is spoken of in a mediæval document,[91] it seems not impossible that there may have been a Norman castle on this site, as we constantly find such small fortifications placed to defend a ferry or ford. It is probable that Ethelfleda's borough was destroyed at an early period by the Northmen, for Runcorn was not a borough at Domesday, but was then a mere dependency of the Honour of Halton. _The Burhs of Edward the Elder._ HERTFORD.--Two burhs were built by Edward at Hertford in 913, one on the north and the other on the south side of the river Lea. Therefore if a burh were the same thing as a motte, there ought to be two mottes at Hertford, one on each side of the river; whereas there is only one, and that forms part of the works of the Norman castle. Mr Clark, with his usual confidence, says that the northern mound has "long been laid low";[92] but there is not the slightest proof that it ever existed except in his imagination. Hertford was a borough at the time of Domesday. No earthworks remain.