20, the accent over the _a_ in _{'a}ld_ is marked in the MS., though the vowel was not originally long.
Even a glance at this comparative table reveals a peculiarity of the Wessex dialect which properly belongs neither to Mercian nor to Modern English, viz.

the use of the diphthong _ea_ (in which each vowel was pronounced separately) instead of simple _a_, before the sounds denoted by _l_, _r_, _h_, especially when another consonant follows.
We find accordingly such Wessex forms as _eall_, _ceald_, _fealleth_, _-feald_, _gealla_, _healf_, _healt_, _nearu_, _eald_, _seald_, _weall_, _gearo_, where the Old Mercian has simply _all_, _cald_, _falleth_, _-fald_, _galla_, _half_, _halt_, _naru_, _ald_, _sald_, _wall_, _iara_.

Similarly, Wessex has the diphthongs _{-e}a_, _{-e}o_, in which the former element is long, where the Old Mercian has simply _{-e}_ or _{-i}_.

We find accordingly the Wessex _c{-e}ace_, _{-e}ac_, _{-e}age_, _sc{-e}ap_, as against the Mercian _c{-e}ke_, _{-e}k_, _{-e}ge_, _sc{-e}p_; and the Wessex _l{-e}ogan_, _l{-e}oht_, as against the Mercian _l{-i}gan_, _l{-i}ht_.
I have now mentioned nearly all the examples of Old Mercian to be found before the Conquest.

After that event it was still the Southern dialect that prevailed, and there is scarcely any Mercian (or Midland) to be found except in the Laud MS.