Natyashastra
मध्ये चैवात्र कर्तव्ये द्वे रेखे तिर्यगूर्ध्वगे । तयोः कक्ष्याविभागेन दैवतानि निवेशयत् ॥ २३॥
In its middle should be drawn two lines vertically and horizontally (i.e parallel to the sides), and in the apartments made by these lines, should be installed the different gods.
english translation
madhye caivAtra kartavye dve rekhe tiryagUrdhvage । tayoH kakSyAvibhAgena daivatAni nivezayat ॥ 23॥
hk transliteration by Sanscript