Agniveshyagrihyasutra 1.1.1.16

1.1.1.16

dakṣīṇenāgniṃ saṃspṛṣṭvā madhyamayā prācīnakumbām uttareṇāgniṃ saṃspṛṣṭvā madhyamayā prācīnakumbām apareṇāgniṃ prāṅmukha upaviśati \

To the south of the fire, having touched the middle one, [he places an enclosing stick] with its thicker end pointing east; to the north of the fire, having touched the middle one, [he places an enclosing stick] with its thicker end pointing east; to the west of the fire he sits facing east.