The first attempt at a theory of the metrical structure of the alliterative line was made by Lachmann. He based his theory on the form of verse created by Otfrid, in imitation of Latin models, which consists of a long line of eight accents, separated by leonine rhyme into two sections each of four accents alternately strong and weak.[17] The laws of the rhyming and strophic verse of Otfrid were applied by Lachmann to the purely alliterative verses of the Old High German _Hildebrandslied_, and this system of scanning was further applied by his followers to the alliterative verse of Old English, the true nature of which was long misunderstood on the Continent. In England itself a sounder view of the native alliterative verse was propounded by Bishop Percy as early as 1765, in his _Essay on the Metre of Pierce Plowman_ published along with his well-known _Reliques of Ancient English Poetry_, not to speak of the earlier writings of G. Gascoigne (1575) and James VI (1585). But the number and authority of some of Lachmann's followers are such that some detailed account of their theories must be given.[18] § =16. The four-beat theory= of the alliterative verse, based on the assumption that each of the two sections must have had four accented syllables to bring out a regular rhythm, was applied by Lachmann himself only to the Old High German _Hildebrandslied_,[19] while on the other hand he recognized a freer variety with two chief accents only in each section, for the Old Norse, Old Saxon, and Old English. The four-beat theory was further applied to the Old High German _Muspilli_ by Bartsch,[20] and to the rest of the smaller relics of Old High German verse by Müllenhoff.[21] The next step was to bring the Old Saxon _Heliand_ and the Old English _Beowulf_ under this system of scansion; and this was taken by M. Heyne in 1866 and 1867. But the metre of _Beowulf_ does not differ from that of the other alliterative poems in Old English, and these in their turn were claimed for the four-beat theory by Schubert,[22] but with this important modification, made before by Bartsch, that side by side with the usual four-beat sections there were also to be found sections of three beats only. One obvious difficulty in applying the theory of four strongly marked beats to the Old English half-lines or hemistichs is this, that in Old English these hemistichs consist in very many cases of not more than four syllables altogether, each one of which would on this theory have an accent to itself. To meet these cases E. Jessen[23] started the theory that in certain cases pauses had to be substituted for 'beats not realized'. A further modification of the four-beat doctrine was introduced by Amelung,[24] who maintained that in the metre of the _Heliand_ each hemistich had two primary or chief accents and two secondary or subordinate accents. In order to bring the verse under this scansion he assumes that certain syllables admitted of being lengthened.