英語訳
[Continued from previous page]...separated from the center of the earth by more than 647,338,690 li.
As for the other distances, near and far, each has its methods of calculation and instruments of measurement.
[Interlinear note: You Xiong (游熊) states: "Measuring instruments are to astronomers what the plumb line, ink-cord, compass, and square are to craftsmen. Originally, the Spiritual Terrace Observatory (靈臺) possessed only such instruments as the gnomon (圭表), the shadow-definer (景符), the simplified armilla (簡儀), and the armillary sphere (渾天儀). The new methods of today follow what the ancient sages and worthies of the Western Regions added and installed, and thus there are now the quadrant (象限儀), the universal instrument (百游儀), the horizon instrument (地平儀), the crossbow instrument (弩儀), the celestial ring (天環), the celestial globe (天球), the sextant (紀限儀), the planispheric astrolabe (渾蓋簡平儀), the ecliptic-equatorial instrument (黄赤全儀), and other such devices — all of extraordinary ingenuity and precision. Beyond these, there are further instruments for measuring shadows: the horizontal sundial (地平晷), the vertical sundial (立晷), the universal sundial (百游晷), the pinhole sundial (通光晷), the pillar sundial (柱晷), the tile sundial (瓦晷), the bowl sundial (椀晷), the cross sundial (十字晷), the star clock (星晷), and the moon clock (月晷). When overcast or rainy weather is encountered, there are the self-striking clock (自鳴鐘), the sand-glass (沙漏), and the water-clock (水漏). For observing the heavens, there is the telescope (遠鏡), by which the boundaries of celestial objects appear clearly defined and even the most minute star-bodies can be discerned. Among all these instruments and dials, the telescope is by far the most ingenious. These are truly not wild or unfounded words, nor are they mere speculation — they are things that do not err by even a hair's breadth."]
Moreover, high and low positions are still fixed, and the revolutions of the celestial bodies as they traverse the heavens can all be measured. For example, the sun is positioned in the middle of the Seven Luminaries, and in approximately one shi (roughly two hours), following the motion of the Heaven of the Prime Mover, it travels 9,040,000 li. The heaven of the fixed stars (経星天) lies above the Seven Luminaries, and in approximately one shi, following the motion of the Heaven of the Prime Mover, it travels 107,200,000 li — which is several tens of times faster than the sun's motion, owing to its proximity to the Heaven of the Prime Mover.
[Interlinear note: Jie Zi (掲子) states: "Combining a person's breathing with the motion of Heaven to make a calculation: in one day and one night, a person takes 25,200 breaths. Heaven completes one full revolution in one day and one night. Calculating per breath: the celestial position in which the moon is lodged corresponds to a motion of 120 li. The celestial position in which the sun is lodged corresponds to a motion of more than 4,004 li. The celestial position in which Mars is lodged corresponds to a motion of more than 6,837 li. The celestial position in which Jupiter is lodged corresponds to a motion of more than 31,620 li. The celestial position in which Saturn is lodged corresponds to a motion of more than 51,325 li. The celestial position in which the fixed stars are lodged corresponds to a motion of more than 80,509 li. The celestial position of the Prime Mover corresponds to a motion of more than 160,161,467 li."]
It is clear that the various stars occupy positions of varying height in the heavens, and their distances from the celestial equator also differ. Each has its own deferent circle (本行) and epicycle (本輪), and each has its two orbital paths and two poles (二道二極). For this reason, their motion through the heavens varies in speed, and their physical forms differ in size. However, because they are at such an immeasurably great distance from the earth, even those that appear large when gazed up at are actually minute. As for the fine ones — such as the Milky Way (天河) and the Praesepe cluster (積尸) — although their stars are numerous, one cannot discern them individually as stars. If a person were to look down at the earth from the position of the stars, the earth would certainly appear no larger than a single mote of dust, impossible to see.
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**The Sizes of the Star-Bodies (星体大小)**