Due east, the middle of the thunder trigram
Zhen is the trigram of thunder and the eldest son, and Mao sits at its exact middle, with Jia on its north side and Yi on its south. This matters most for the incoming dragon: a ridge that drops into the site from Mao enters on the strongest line of the east, and the old form books rate a clean east entry well.
Mao is also the seat of a west-facing stone, sitting Mao and facing You, where the sun rises behind the grave and sets in front of it. As a facing, Mao is a house that looks straight into the sunrise with its back on You.
Heaven's Mandate and the three auspicious mountains
On our luopan Mao carries Tianming, Heaven's Mandate: proper standing, legitimacy, taking up what one is handed. It is a common star, yet Mao itself is counted among the three auspicious mountains with Hai and Geng, and Lai Buyi's Cui Guan Pian treats a Zhen dragon with respect.
In the Tianxing method the star never does the judging. The order is the ridge first: is the spine clear, does it drop and rise again before the site, do the guarding hills close around it? Only then is the dial turned to Tianming, and the star read as a check on what the land already showed.
What this means on the ground
For a house, stand just inside the front door with your back to it and look out. Hold the luopan level, clear of steel, and keep the middle of three readings. A reading of 82.5 to 97.5 means the house faces Mao and sits on You. For a grave, stand behind the stone and read the way the face points.
Where the number lands inside Mao matters. Near 90 it sits on the equinox line. Toward 82.5 it leans on Jia, toward 97.5 on Yi, and within two degrees of either line it is riding the boundary. The trade turns it a degree or two back into Mao before the stone is cut.
Common mistakes
The first is a phone set to true north. The luopan uses a magnetic needle, so every figure on this site is a magnetic bearing; in parts of North America and Australia the difference passes ten degrees, enough to carry a Mao reading into Jia or Yi. The second is reading from the wrong spot, on the doorstep facing the house, or beside the stone.
The third is copying a book that lists east as lucky and setting a stone on 90 without walking the ridge behind it. Mao is auspicious only when a real dragon enters on it; a flat lot stays a flat lot whatever the dial says.
Questions people ask
What direction is Mao on a feng shui compass?
Due east: the 15 degrees from 82.5 to 97.5 on the luopan, centred on 90. It is a magnetic bearing, so set a phone compass to magnetic north before comparing. Jia lies just north of it, Yi just south.
What does sitting Mao facing You mean?
The back of the stone or house points to due east and the front looks to due west, so the sun rises behind the seat and sets in front of it.
Is Mao a lucky mountain in feng shui?
Mao is one of the three auspicious mountains in the Tianxing school, with Hai and Geng, under the star Heaven's Mandate. That ranks a direction, not your land. A master still walks the ridge to see whether a dragon enters on Mao.
If your grave or door reads Mao, send Master Zhang three readings and a photo of the ridge behind it, and he will tell you in a site reading whether a dragon really enters there.