On glimpsing, for the only time, the end of a rainbow

A great upswelling splash of golden fire Engulfing sheds, a wharf, a ship's hull, flared Its moment down at water's edge below The bridge-borne road, tire-slithery with rain. The bow shone anchored there, the crescent reds And blues a harbor-dazzling aegis fit For Uranos, the titan Sky, of gods The ancient primal metaphor of mind. No Pluto's hoard was there, no cache of coins Nor treasury of gems rewarding greed; Only the instant sign I've seen at last - And having found it feel a strange content - When light and gravity, as force and mass, Flung beauty, absolute, to my eyes' grasp.