《宋史·志·卷一》
占验日月星三辰隐藏出现，专用地弦地际作为标准，自然应当暗自与天相合。
候三辰伏见，专以纮际为率，自当默与天合。
When checking the rising and setting of the sun, the moon and the stars, the horizon line and the horizon should be used as the standard, and they should naturally correspond with the celestial phenomena.