Thanks! Always been an interest of mine. Years ago I started tracing out where the shadow of the peak of our garage is cast onto our driveway but haven't kept up with the project. The solstices and equinoxes at solar noon have been chisled into the concrete, but nothing else. Already the first page of the article has me thinking about that project again. Hopefully the Spring Equinox is a sunny day and I can put that whole curve onto the driveway. I was thinking about it on this last solstice as I shovelled feet of still falling snow from the driveway. Obviously, no marks were made that day.