Checking for verticality.
Then we prepared to set a stake on the west fence along a line to the horizon point where the sun would set, but an enormous cloud bank quickly moved up and into the way.
We made an approximation then watched the clouds boil.
The forecasted thunderstorms never materialized. We got a few sprinkles of rain overnight and the overcast this morning kept us from setting a stake for the sunrise. Oh well – this is a 40-year project and by successive approximation we'll establish points for the equinoxes and cross-quarter days as well as the solstices, and who knows what else.