Brihat Samhita
क्षौमं चतुःसूत्रकसन्निबद्धं षडङ्गुलं शिक्यकवस्त्रं अस्याः । सूत्रप्रमाणं च दशाङ्गुलानि षडेव कक्ष्य उभयशिक्यमध्ये ॥ २६-०६ ॥
The Jyotiṣaka shall take two square pieces of white silk, the side being six inches long and attach the four ends of each to the ends of four strings each ten inches long; the length of the string attached to the middle of the beam shall be six inches.
english translation
kSaumaM catuHsUtrakasannibaddhaM SaDaGgulaM zikyakavastraM asyAH । sUtrapramANaM ca dazAGgulAni SaDeva kakSya ubhayazikyamadhye ॥ 26-06 ॥
hk transliteration by Sanscript