Twice yearly, an accident of solstice, orientation and geometry sends golden shafts of setting sun straight through the grid from river to river, west to east, an occasion that would be celebrated by people less in a hurry.
Mr. House says an east-west orientation is preferred because latitude works with the sun's motion, making it easy for an individual who wants morning sunlight in the breakfast room to position it on the west side of the home, with east-facing windows.
Find this orientation by looking through the crystal at the sky at a time when you can see the sun, mark the sun's direction on the crystal, and your mark will always point towards the sun when you match the beams from even a tiny patch of blue in an otherwise overcast sky.