" An experiment with a h2o-crammed glass sphere was carried out and al-Farisi showed the extra refractions mainly because of the glass can be disregarded in his design.[74][c] As he pointed out in his Kitab Tanqih al-Manazir (The Revision on the Optics), al-Farisi employed a sizable clear vessel of glass in The form of a sphere, which was stuffed w