Xu as water mouth, sitting and dragon
In Jiangxi, Xu is most often met as a water mouth. A site facing south-east or east sends its water out west, and an outlet in Xu must be closed: two hill feet overlapping, a boulder, a bend, anything hiding where the water goes. An open, straight outlet on Xu is a loss of water, whatever the degree.
As a sitting mountain, Xu puts the stone's back to the west by north-west and its face to Chen. The dragon arrives through Qian or Xin and should settle as a broad low mound, not a sharp ridge; Earth between two Metals asks for a thick back.
Tiankui, the Dipper's first star, as confirmation
Xu carries Tiankui, the Heaven's Chief, the Dipper's first star. Kui stands for examinations, writing and taking the lead. It is a regular star, and Xu is in neither the three auspicious nor the six elegant, so the Tianxing reading here is modest: form first, star second, and a failed form is not rescued by the star.
A clean pointed peak on Xu is a writing-brush peak, and Tiankui agrees with it. One pairing: Xu faces Chen, and Chen carries Tiangang, the Dipper's handle, so sitting Xu facing Chen has the Dipper's head behind and its handle in front. A fact of the plate, not a verdict on a plot.
What this means on the ground
Stand inside the door with your back to it at a house, behind the stone sighting along its face at a grave. Level the luopan, read three times a step apart, and take the middle. Stay clear of steel and set any phone compass to magnetic north.
Xu runs from 292.5 to 307.5, and 296 to 304 is squarely inside. From 293 to 295 you are near Xin, where Earth gives way to Metal; from 305 to 307 you are near Qian. Either way the stone turns a degree or two inward on the fen jin. For a water mouth, sight from the stone to where the water disappears.
Common mistakes
The first is to measure the water mouth from the stream bank; the mouth is always sighted from the stone. The second is a map compass on true north, which in Vancouver or Sydney can push a 300 degree site into Qian. The third is to treat Tiankui as a result: a book says the Dipper's first star means exams, so a Xu facing is chosen for a student without checking that the hill on Xu is whole.
The fourth is to confuse Xu with Qian. They are neighbours, but Qian is a Metal corner trigram with Tianjiu and Xu an Earth branch. The fifth is a stone on the 292.5 line.
Questions people ask
What direction is Xu on a feng shui compass?
Xu is 300 degrees, west by north-west, covering 292.5 to 307.5. It is the eleventh branch, the dog, an Earth mountain between Xin and Qian. Its opposite is Chen at 120 degrees. On our luopan it carries Tiankui.
What does it mean if my water mouth is in Xu?
It means the water leaves towards the west by north-west, neither good nor bad by itself. Look at the outlet from the stone: if hills, trees or a bend hide the last of the water, the mouth is closed; if it runs straight away, the site is losing water.
Is sitting Xu facing Chen a good orientation?
It is common for a site whose dragon comes from the north-west and whose water leaves east or south. It works when the back is a broad firm mound and the view to Chen is open with a peak. The degree alone does not make it good.
Ask Master Zhang for a site reading if your water mouth or your family stone falls on Xu.