Smoked glass
The glass is honest against a known radius, not against a thumbnail.
Every open morning Ewan soots the glass on a brass template we keep in the station. If the soot drifted, Fourth does not open.
A thumbnail is a story from Redlands Mesa. Smoked glass is a number. Arc radius is written on the stake card in tenths, entry and exit separate, because Grand Junction clay does not wear a sole evenly.
We will show you the pale soot where the exit went straight. We will not show you a tablet cartoon of bounce. If you need a cartoon number, the strip on North Avenue still sells those.