The station of ÆSICA, according to the Notitia, was about the year 430, garrisoned by the _cohors prima Astorum_.[115] Horsley (writing in 1731) observes, that no inscriptions had been found here mentioning the first cohort of the Asti, or any other cohort. In 1761, however, an inscription was dug up in this station, which is now deposited in the museum at Newcastle-upon-Tyne, recording that in the reign of Alexander Severus (200 years before the date of the Notitia) the ‘cohors secunda Asturum’ rebuilt a granary here which had fallen into decay from age—‘horreum vetustate conlabsum.’ It is to be observed that the spelling of ‘Asturum’ is similar to that of the inscription at CILURNUM, and we do not find that the _second_ cohort, either of the Asti or Astures, is mentioned elsewhere as part of the Roman auxiliary forces in Britain. Near the eastern gateway of the station there has been lately dug up a large mural tablet, shewn in the wood-cut, and bearing the following inscription: [Illustration: IMP. CÆS. TRAI[A]N. HADRIA NO AVG. P[ATRI] P[ATRIÆ]. To the emperor Cæsar Trajanus Hadria- nus Augustus, the father of his country. ] It is not probable that this slab has been derived from the Vallum, which is upwards of a quarter of a mile from the station.[116] Why the upper part of the tablet was left blank does not appear; enough, however, has been inserted to support the theory, that Hadrian built the Wall. Although several of the stations were probably built before the Wall, and were quite independent of it, this can scarcely have been one of them; its position seems to indicate that it was called into existence in order to accommodate the mural garrison. [Illustration: _SURVEYED BY I. T. W. BELL 1860_ _A. Reid’s Lithog. 117 Pilgrim St. Newcastle._ Plan of AN ANCIENT WATER COURSE EXTENDING FROM SAUGHY BIG WASH POOL TO ÆSICA GREAT-CHESTERS. ] [Sidenote: ETYMOLOGY OF ÆSICA.] Celtic authorities all agree in tracing the name ÆSICA to a word signifying _water_. The propriety of such an appellation does not at first sight appear. The camp is far from either the eastern or western sea; no lake is visible from its ramparts; the only water which is near is the Haltwhistle-burn, a somewhat tiny stream. The low ground to the south has a fenny aspect, but the station itself stands high and dry, though upon a part of the mural ridge less elevated than usual. It is not improbable that it may have derived its name from an aqueduct which leads the water from the Greenlee-lough to the camp. As this water-course has hitherto escaped the notice of writers upon the Wall, and is a work of considerable interest, a somewhat detailed description of it may be allowable. THE WATER-COURSE AT ÆSICA.