One stone threshold shown in two dated states, the earlier tool-marked surface above giving way to the later worn hollow below.

World Memory · Station S52 · material-memory investigation

What worethe stone?

One threshold, two dated views — c. 1723 and c. 2019. Between them, nothing that happened once. Only passage, and passage, and passage.

Follow the surface down
the low point, where the tooling has gone

view dated c. 1723 · the surface, still whole

The chisel's rhythm is still legible, edge to edge.

The arris still reads as a straight, unrounded edge in this view.edge · earlier view

No path across it yet. The bedding joint reads even; dust lies where dust falls.dust · undisturbed

Nothing here happened once.

repeated passage?possibility mark · not recorded

hand contact?possibility mark · not recorded

grit / sweeping / weather?none of these can be isolated

still original here — tool facets intact

the grain begins to soften

tooling absent · the low point

polish, where hands rest

trace the grooveMove down the stone with a finger or the cursor. The cut deepens under you and the comparison marks surface; lift away and the surface returns.

the later form

The same stone, swept between its dated states.

Drag through and the hollow arrives — not as a cut, but as an absence. Where the wear is deepest, the earlier tooling has no trace left to compare against.

The threshold as recorded in the later view, its centre hollowed and polished.
The same threshold drawn back toward its earlier, tool-marked state.
c. 1723 c. 2019

tooling intact to the edgeearlier view · arris

tooling gone in the hollowlater view · centre

polish along the line of passagecause not isolated

dust and lichen only beside itobservation, not rate

The stone remembers pressure, not intention.

stone-rubbing field tag — evidence & limits

subjectOne threshold surface; a single continuous stone, compared with itself.

viewsEarlier view, dated c. 1723. Later view, dated c. 2019. Both dates approximate.

methodVisual comparison of two dated views of the same surface: tooling legibility, arris profile, polish distribution, dust and lichen coverage.

claimCumulative wear, inferred — not measured. No single mechanism is asserted.

sources

Source link not supplied. No source address for either view reached this station, so nothing is linked and nothing is invented. c. 1723 and c. 2019 stand only as the Station's two comparison inputs.

explicit limits

Both dates are approximate. No depth, area or volume of loss was ever recorded, so nothing here may be read as a rate. Cumulative wear is an inference drawn from two views: footfall, hand contact, grit, sweeping, weather and repair cannot be isolated from one another, and no control surface on the same stone was documented. The earlier state shown on this page is drawn back from the earlier view — a reconstruction, not a second photograph.