LIMERICK  , a name which has been adopted to distinguish

Roman boundary till the empire fell . The southern part was a certain form of verse which began to be cultivated in the middle different . The upper Rhine and upper Danube are easily of the 19th century . A limerick is a kind of burlesque epigram, crossed . The frontier which they form is inconveniently long, written in five lines . In its earlier form it had two rhymes, enclosing an acute-angled wedge of foreign territory—the modern the word which closed the first or second line being usually Baden and Wurttemberg . The German populations of these employed at the end of the fifth, but in later varieties different lands seem in Roman times to have been scanty, and Roman rhyming words are employed .. There is much uncertainty as subjects from the modern Alsace and Lorraine had drifted across to the meaning of the name, and as to the time when it became the river eastwards . The motives alike of geographical con-attached to a particular species of nonsense verses . According venience and of the advantages to be gained by recognizing these to the New Eng . Diet . " a song has existed in Ireland for a very movements of Roman subjects combined to urge a forward considerable time, the construction of the verse of which is policy at Rome, and when the vigorous Vespasian had succeeded identical with that of Lear's " (see below), and in which the the fool-criminal Nero, a series of advances began which gradually invitation is repeated, " Will you come up to Limerick ?

" closed up the acute

angle, or at least rendered it obtuse . Unfortunately, the specimen quoted in the New Eng . Diet. is not The first advance came about 74, when what is now Baden only not identical with, but does not resemble Lear's . Whatever was invaded and in part annexed and a road carried from the be the derivation of the name, however, it is now universally Roman base on the upper Rhine, Strassburg, to the Danube used to describe a set of verses formed on this model, with the just above Ulm . The point of the angle was broken off . The variations in rhyme noted above:— second advance was made by Domitian about A.D . 83 . He " There was an old man who said ' Hush! pushed out from Moguntiacum, extended the Roman territory I perceive a young bird in that bush ! ' east of it and enclosed the whole within a systematically de- When they said, 'Is it small ? ' limited and defended frontier with numerous blockhouses along He replied, Not at all! it and larger forts in the rear . Among the blockhouses was one It is five times the size of the bush.' " which by various enlargements and refoundations grew into the The invention, or at least the earliest general use of this form, well-known Saalburg fort on the Taunus near Homburg . This advance necessitated a third movement, the construction of a frontier connecting the annexations of A.D .

7a and 83 . We know the line of this frontier which ran from the

Main across the upland Odenwald to the upper waters of the Neckar and was defended by a chain of forts . We do not, however, know its date, save that, if not . Domitian's work, it was carried out soon after his death, and the whole frontier thus constituted was reorganized, probably by Hadrian, with a continuous wooden palisade reaching from Rhine to Danube . The angle between the rivers was now almost full . But there remained further advance and further fortification . Either Hadrian or, more probably, his successor Pius pushed out from the Odenwald and the Danube, and marked out a new frontier roughly parallel to but in advance of these two lines, though sometimes, as on the Taunus, coinciding with the older line . This is the frontier which is now visible and visited by the curious . It consists, as we see it to-day, of two distinct frontier works, one, 'known as the Pfahlgraben, is an earthen mound and ditch, best seen in the neighbourhood of the Saalburg but once extending from the Rhine southwards into southern Germany . The other, which begins where the earthwork stops, is a wall, though riot a very formidable wall, of stone, the Teufelsmauer; it runs roughly east and west parallel to the Danube, which it finally joins at Heinheim near Regensburg . The Pfahlgraben is remark-able for the extraordinary directness of its southern part, which for over 50 M. runs mathematically straight and points almost absolutely true for the Polar star . It is a clear case of an ancient frontier laid out in American fashion .

This frontier remained for about zoo years, and no doubt in that long

period much was done to it to which we cannot affix precise dates . We cannot even be absolutely certain when the frontier laid out by Pius was equipped with the Pfahlgraben and Teufelsmauer . But we know that the pressure of the barbarians began to be felt seriously in the later part of the 2nd century, and after long struggles the whole or almost the whole district east of Rhine and north of Danube was lost—seemingly all within one short period—about A.D . 250 . The best English account will be found in H . F . Pelham's essay in Trans. of the Royal Hist . Soc. vol . 2o, reprinted in his Collected Papers, pp . 178-211 (Oxford, 1910), where the German authorities are fully cited . (F . _J .