It is a sketch, drawn by a country clergyman at some unknown point in the past and preserved in private manuscript notes. That the mill existed at all is known only because someone thought to draw its chute, the wooden or stone channel that directed water onto the wheel, before the evidence disappeared entirely.

Horizontal mills, sometimes called Norse mills or tide mills depending on their setting, were among the most common industrial structures in early medieval Ireland. Unlike the vertical waterwheel familiar from later centuries, a horizontal mill used a wheel laid flat beneath the millhouse, turned directly by a jet of water forced through a narrow chute. The arrangement was simple, effective, and widespread across early Christian Ireland, where such mills ground grain for monasteries and farming communities alike. The Clonickilvant example was recorded by the Reverend W. Falkiner of Killucan, whose manuscript notes, cited by A. T. Lucas in 1969, were at that time held by Mrs Ruth Bayly-Vandeleur of Wardenstown, County Westmeath. Beyond the sketch of the chute, little else is documented about the structure's original dimensions, date, or precise location within the townland.

What this amounts to is a place that exists almost entirely on paper, its physical remains long gone and its record reduced to a single drawn detail in a privately held manuscript. That such a fragment was noticed and preserved at all says something about the quiet persistence of local antiquarian interest in the Irish midlands.