the name of the third rampart or defence that had been built or repaired by the Romans against the incursions of the North Britons. It is called by the people in the neighbourhood Graham's Dike, from the notion that one Graham, or Grimus, first made a breach in it after the retreat of the Romans out of Britain. The first barrier erected by the Romans was the chain of forts made by Agricola from the frith of Forth to that of Clyde, in the year 81, to protect his conquest from the inroads of the Caledonians. The second was the vallum or dike thrown up by Adrian in the year 121. It terminated on the western side of the kingdom at Arclodunum or Brugh, on the Solway sands, and was supposed to have reached no farther than Pons Elyi or Newcastle on the eastern; but from an inscription lately discovered, it appears to have extended as far as the wall of Severus. This rampart of Adrian's was situated much farther south than Agricola's chain; the country to the north having been either, according to some authors, recovered by the native Britons after the departure of Agricola, or, according to others, voluntarily slighted by Adrian. However, this work of Adrian's did not long continue to be the extreme boundary of the Roman territories to the north in Britain; for Antoninus Pius, the adopted son and immediate successor of Adrian, having, by his lieutenant Lollius Urbicus, recovered the country once conquered by Agricola, commanded another rampart to be erected between the friths of Forth and Clyde, in the track where Agricola had formerly built his chain of forts. The great number of inscriptions which have been found in or near the ruins of this wall or rampart, to the honour of Antoninus Pius, leave us no room to doubt its having been built by his direction and command. If the fragment of a Roman pillar with an inscription, now in the college library of Edinburgh, belonged to this work, as is generally supposed, it fixes the date of its execution to the third consulship of Antoninus, which was A.D. 140, only twenty years after that of Adrian, of which this seems to have been an imitation. This wall or rampart, as some imagine, reached from Caer-ridden on the frith of Forth to Old Kirkpatrick on the Clyde; or, as others think, from Kinniel on the east to Dunglass on the west. These different suppositions hardly make a mile of difference in the length of this work, which, from several actual mensurations, appears to have been 37 English or 40 Roman miles. Capitolinus, in his life of Antoninus Pius, directly affirms that the wall which that emperor built in Britain was of turf. This in the main is unquestionably true, though it is evident (from the vestiges of it still remaining, which not very many years ago were dug up and examined for near a mile together) that the foundation was of stone. Mr Camden also tells us that the principal rampart was faced with square stone, to prevent the earth from falling into the ditch. The chief parts of this work were as follows: 1. A broad and deep ditch, whose dimensions cannot now be discovered with certainty and exactness, though Mr Pont says it was 12 feet wide. 2. The principal wall or rampart was about 12 feet thick at the foundation, but its original height cannot now be determined. This wall was situated on the south brink of the ditch. 3. A military way on the south side of the principal wall, well paved, and raised a little above the level of the ground. This work, as well as that of Adrian, was defended by garrisons placed in forts and stations along the line of it. The number of these forts or stations, whose vestiges were visible in Mr Pont's time, was 18, situated at about the distance of two miles from each other. In the intervals between the forts there were turrets or watch-towers; but the number of these, and their distance from each other, cannot now be discovered.

It is not a little surprising, that though it is now more than 1600 years since this work was finished, and more than 1300 since it was slighted, we can yet discover, from authentic monuments which are still remaining, by what particular bodies of Roman troops almost every part of it was executed. This discovery is made from inscriptions upon stones, which were originally built into the face of the wall, and have been found in or near its ruins. From these inscriptions it appears in general, that this great work was executed by the second legion, the vexillationes of the sixth legion and of the twentieth legion, and one cohort of auxiliaries. Some of these inscriptions have suffered greatly by the injuries of time and other accidents; so that we cannot discover from them with absolute certainty how many paces of this work were executed by each of these bodies of troops. The sum of the certain and probable information contained in these inscriptions, as it is collected by Mr Horsley, stands thus:

| Description | Paces | |--------------------------------------------------|-------| | The second legion built | 11609 | | The vexillation of the sixth legion | 7411 | | The vexillation of the twentieth legion | 7801 | | All certain | 26815 | | The vexillation of the twentieth legion, the monument certain, and the number probable | 3411 | | The same vexillation on a plain monument, no number visible, supposed | 3500 | | The sixth legion, a monument, but no number, supposed | 3000 | | Cohors prima Cugernorum | 3000 |

Total: 39726 or 39 miles 726 paces, nearly the whole length of the wall. It would be both useful and agreeable to know how long these troops were employed in the execution of this great work. But of this we have no information. Neither do we know what particular bodies of troops were in garrison in the several forts and stations along the line of this wall, because these garrisons were withdrawn before the Notitia Imperii was written.

Though we cannot discover exactly how many years this wall of the emperor Antoninus continued to be the boundary of the Roman territories in Britain, yet we know with certainty that it was not very long. For we are told by an author of undoubted credit (Dion Cassius, lib. lxxiii.), that, in the reign of Commodus, A.D. 180, "he had wars with several foreign nations, but none so dangerous as that of Britain; for the people of the islands having passed the wall which divided them from the Romans, attacked them, and cut them to pieces."