Proportion:

acoustics acute angles agreeably analogy aqueous humour arranged arts body called centre point circle circular circumference colour combinations composed configuration crystalline lens curved line curvilinear figure diameter diatonic scale double octave effects elements ellipse endeavour equal equidistant equilateral triangle former essay four geometric beauty geometric principle geometrical figures geometry of harmony give gonals Grecians harmonic ratios harmonious division harmony of form homogeneous imitation inscribed intersections iris kind line drawn mediant membrane mode of division monochord musical composition musical scale number of degrees number of vibrations oblique oblong obtuse angle obtuse-angled isosceles perfect perimeter plane Plate XV Plato portion posterior chamber proper pupil quantity racter radius range of human rays rectangle rectilinear figures relations relative proportion retina rhombus right angle rules secondary semitone shown in figure sides simple solid angle sound straight line string three primary tion tone tonic transparent media treatise variety various vertical diagonal vitreous humour