ORDER OF OGHAM LETTERS

        There are two different orders of the Ogham letters.  The order
    given in my poem is the older of the two.  It is known as the B.L.N.
    version as opposed the B.L.F. version.  Robert Graves devotes two
    chapters in his White Goddess to this question of order.  It is
    strongly suggested that the book be obtained and read.

        The following two quotes are from the book and are just to serve
    as a memory jog; not a full explanation!

        "What complicates the case is that the ancient Irish word for
    'alphabet' is 'Beth-Luis-Nion' which suggests that the order of the
    letters in the Ogham alphabet was orginally B.L.N. though it had
    become B.L.F. before the ban on inscriptions was lifted."  p. 116


        "But is not the answer to our question to be found in the
    'Battle of the Trees'?  What distinguishes the BLFSN from the BLNFS
    is that the letter N, 'Nion' the ash, the sacred tree of the God
    Gwydion, has been taken out of the dead period of the year, where it
    is still in black bud, and put two months ahead to where it is in
    leaf, while 'Fearn' the adler, the sacred tree of the God Bran,
    which marks the emergence of the solar year from the tutelage of
    Night, has been thrust back into 'Nion's' place. The BLNFS is a
    trophy raised by Gwydion over Bran.  And is it not strange that a
    few years before the 'Battle of the Trees' was fought in Britain and
    the letter F humbled, the Greeks had made a dead set against their
    F, only retaining it as a numerical sing for 6?  More than this
    happened when the order of the letters changed; Gwydion's ash, N,
    took the place of the fifth consonant, 'Saille' the willow, S, which
    was naturally sacred to Mercury, or Arwan; and Gwydion thereupon
    became an oracular god.  Also, Amathaon who had evidently been a
    willow-god, S, took Bran's place at F and and became a fire-god in
    the service of his father Beli, God of Light.  It only remained in
    this General Post for Bran to take over the maritime ash that
    Gwydion has relinquished and sail away on his famous voyage to one
    hunderd and fifty islands; yet sailing was no novelty to him, the
    tradition preserved by Virgil being that the first boats that ever
    took to the water were alder-trunks."  p. 244