Geometric arrow tattoo on the ribs

The levels came back on Tuesday and Mr Pardoe still insists the sluice at Coldharbour sits a hand's width too high. I have told him twice that water does not climb a bank because a man would like it to, and he has taken to calling me the girl with the chalk. Still, I have been out at the dyke every morning since, sighting along the stakes with the theodolite your father lent me, and I think I have found his error. It is in the stake at the bend, which someone moved in the spring and did not write down.

I walked the line again yesterday with the old field book open on my knee. Every bearing in it points the same way, a little north of where the river wants to go, as though the whole county had been set down by somebody leaning forward. I copied the marks the book uses in its margins, the chevrons for the sluice gates and the nested squares for the culverts, and when I joined them with a ruler I saw the shape the whole network makes. It is a single narrow arrow with a pointed tip, all doubled-back lines and small sharp steps, aimed squarely at the church tower in Wisbech.

Mr Pardoe came down to the bank at dusk to watch me pack up. He stood with his hands behind his back for a long time, then asked whether I meant to move the stake or leave it for the next fool. I said I would leave it. Some things are kinder left pointing wrong, and besides, the water always finds its own way down.

Write soon, and tell me whether the rail line has finally reached Ely. I am tired of hearing about it from people who have never stood in a ditch.

Yours in mud, Margaret