《明史·志·卷七》
第八，讨论日月离交点的远近及真正会合、视觉会合的原因，以确定距午时差的准确比率，以订正日月食。
其八，议日月去交远近及真会、视会之因，以定距午时差之真率，以正交食。
Eighthly, discuss the distance between the sun and moon at the nodes, and the causes of true conjunction and optical conjunction, so as to determine the precise ratio of the meridian elongation, and to revise the solar and lunar eclipses.