Natyashastra
अधोऽवलोकनैश्चैव मण्डलावर्तनेन च । आकाशगमने चैव कर्तव्या नाट्ययोक्तृभिः ॥ ९३॥
While moving through the sky, the actor should look downward and move in a circular manner (around the stage).
english translation
adho'valokanaizcaiva maNDalAvartanena ca । AkAzagamane caiva kartavyA nATyayoktRbhiH ॥ 93॥
hk transliteration by Sanscript