On the relevance of Brigid as Matron of Blacksmiths
It is my contention that although blacksmiths and forge-workers of old may have held Brigid to be their patron deity (matron) due to her association with the hearth, "smithcraft" was not representative of her spiritual aspects beyond that association.
Would we say that automobiles should be an emblem of Saint Christopher? Well, for the better part of the 20th century, millions of Roman Catholics world-wide had a little plastic statue of St.Christopher on the dashboard of their cars and/or a St. Christopher medal hanging from their rear-view mirror. So, is an automobile a religious symbol of St. Christopher? Is Jesus to be given the epithet "grave-god" because the graveyard is full of crosses?
I would hope you'd answer: "Er, um, well, sort-of but... I suppose no, not exactly..."
The primary story recalling the mythic-identity of Saint Christopher ("Christ-carrier") was that he once unknowingly carried a wayward child safely across the raging torrent on his shoulders and this tattered child, greatly impressed with his kindness and bravery, turned out to be the Lord Himself. As a consequence, Catholics everywhere ascribed to him the role of Protector of Travelers.
Squadrons of desperate mothers, tens, no, hundreds of thousands, prayed every night to St.Christopher, begging for his intercession with the Lord to protect their sons on their travels overseas, and so it was through several of the wars in the last century. Alas, in later years albeit still hugely popular, the Church decomissioned him, as presenting far too-little historical data to support his actual existence, relegating him to the dust bin of apochrypha.
BRIGANTIA: Protectress and Sovereign
Brigid is almost exclusively rubber-stamped for us these days in the popular Celtophernalia as "a goddess of Poetry, Healing and Smithcraft" and it is the smithcraft I would take to task here. We have no Irish Gundestrup or Reims icons to compare and review here, no Scythian or Roman craftsmen to fossilize some cross-cultural clues for us... None* but one; the Romano Celtic shrine to Brigantia from north Britain...
Above is an 1800 year old artifact bearing an image which we should cherish and hold central to our quests for understanding Her. Yet, somehow, it remains largely overlooked. Yes, the iconography here is almost completely Roman, calling her Brigantia, but portraying her as a sovereignty goddess with a full set of the attributes of Minerva: the spear and shield and the Aegis on her breastplate, and in her hand, the orb as a symbol of her universal rulership. You may recall having seen this particular icon, but honestly, just how often? Why so infrequently?
The Minerval aspect of Brigid accounts for or at least informs many of the bits of lore we have from the Irish and the Scots. The protectress function not only sees her as a guide and guardian of armies and nations but figures equally well in her inspiration to mothers and house keepers as foster mother, blesser of the home-hearth and protector of door, wall and roof. As inspiratrix she guides the creative with her flame of wisdom. As the emblem of the soul of the nation of Ireland to this day and more anciently of Britain, there is little question of her function as a goddess of sovereignty...
But, as usual, instead we are plastered (wattle and daubed?) with the same couple of fragments of Brigid-lore from the Irish hero tales, the sources for which only rarely exceed the first thousand years before our time. Younger yet, the remaining body of lore attributed to Her is actually booty from raids made by the wishful-thinking upon the lore and folkways attributed to the quasi-historical Christian saint bearing her name. I must confess I often have pillaged therein myself, particularly in the wonderful appendices to Campbell's Carmina Gadelica. That material, as beautiful and evocative as it is, bears its unshakable Iron Age pedigree only in that it was field-collected from Scottish folk traditions alive in the years stretching from the time of Charles Dickens through the reign of Queen Victoria. Yes, back when Lady Gregory carried her tablets down from Ben Bulben, summing up for us forever after the three primary aspects of Brigid as "Poetry, Healing, and Smithcraft"...
Quite simply: a Goddess of the Hearth and the sanctity of Fire
There seems to be a significant number of references to the quasi-historical saint, or dearly hoped-for "Celtic Goddess", which indicate an association with fire, and in particular, sacred fires, and a strong and potentially very old set of household hearth-customs, the common ground there being specifically fire-based prayers and ritual activity. Again I will admit to falling back on my own intuition and syncretic tendencies (and some 25 years of ritual experience with Her) and I continually emerge with the conclusion that a primary component of Brigid's identity was focused on the sanctity and utter indespensibility of fire and as such it brought Her veneration to a central, veritably axial, role in every home, first then and foremost as a Goddess of the Hearth.
In my mind, Brigid was likely no more a goddess "of smithcraft" than Saint Christopher was a saint of automobiles.
Certainly She would have been held by the blacksmiths and forge-workers as their patron. The anvil, hammer, and tongs may have been their connection to Her but this only because they were daily workers at a hearth. But proportionally, who worked at hearths? Let us not forget that for every single blacksmith west of the Rhine in the last 2500 years, there were untold millions of housekeeper cooks, working their daily magic, and even more populous yet came all those damp and shivering souls, stumbling in from the cold to huddle-before that blessed radiance glowing at the center of every home, eagerly drawing upon Her power to comfort and heal, to protect and inspire.
* well actually, this "one" seems to be the model or best realized from among several extremely similar but more crude Brigantia-relief versions from the same area and period in the south of Scotland.