卷三·第 165–173 问　认月站、银河、星座次序与太阳远地点

§165. What is the way to recognize these mansions?

第一百六十五问　认识这些月站的途径是什么？

Al-Thurayyā is the best known of the mansions of the Moon and the most evident to the generality of people. So one should start from it, or from any other that one may happen to know, going along the path of the Moon's course towards the east, until al-Dabarān is found about a spear's length from al-Thurayyā; and going from it towards the west about twice that distance, until al-Sharaṭān is found; then one looks for al-Buṭayn between them. When one has identified these four mansions, one learns from them the distance between every two mansions approximately. Then, if one steps from each known mansion an equal distance towards the east and the west, and seeks, along the path of the Moon's course, the stars of the intended mansion as we have described them, or near it and facing it to the north or the south, those stars will be found. One keeps doing this, one after another, until one has gone through all of them, and so comes to know the whole.

苏莱雅是月亮诸站中最有名的，在一般人眼里也最显眼，所以应当从它开始，或者从自己碰巧认得的别的哪一站开始，顺着月亮运行的路径向东走，直到在离苏莱雅约一矛之远处找到代伯兰；再从它向西走约两倍的距离，直到找到谢拉坦；然后在两者之间细看布泰因。认定了这四站，就能从中大致知道每两站之间相隔多远。此后，从每个已知的月站向东、向西各跨出相等的一段，沿着月亮运行的路径，寻找我们描述过的、所要找那一站的星，或在它附近、在它北边或南边与它相对之处，那些星就会被找到。如此一站接一站做下去，直到走遍全部，于是认识了整体。

§166. What is meant by the rising of the mansions?

第一百六十六问　所谓月站之“升”，指的是什么？

What is meant is not their rising from the horizon, for that happens once every day. The rising ascribed to them is rather like the eastern appearance which we have described for the three upper planets. For when the Sun comes near one of the fixed stars it conceals it, and the star's rising takes place by day, or its setting before the twilight has set; this is called its disappearance in the west. This continues until the Sun has passed it far enough that, when the star rises before the Sun, the Sun does not overpower it with the light of dawn; its first appearance in the east in the morning is then its rising, and it is called nawʾ, as though the star nāʾa, that is, rose up. When a mansion rises at the time we have mentioned, its counterpart, called its raqīb (watcher), which is the fourteenth from it, sets at that moment, and this is called its fall (suqūṭ). Between the rising of each mansion and that of the next there are thirteen days, approximately and not exactly, because the stars of the mansions are not all of one magnitude, nor are their latitudes equal and in one direction. The name anwāʾ is applied to the rains, whose times are ascribed to the fall of the mansion setting in the west in the mornings; and bawāriḥ is applied to the winds, which, outside the times of rain, are ascribed to the rising of the mansion emerging from under the rays in the mornings. That holds in the land of the Arabs on account of the times of rain; but the events of the air differ in widely separated places, and even in neighbouring ones when their situations differ, as sea and plain, lowland and highland.

所指的不是它们从地平线升起，因为那每天都有一次。归于它们的“升”，倒像我们前面为三颗上行星所描述的东方出现。因为太阳一靠近某颗恒星就把它遮住，这颗星的升起落在白天，或者它在暮光消失之前就已沉落，这称为它在西方的隐没。这样一直持续，直到太阳越过它足够远，使这颗星在太阳之前升起时，太阳不再以黎明的光压过它；它在清晨于东方的初次出现，就是它的“升”，称为“瑙乌”，仿佛说这颗星“纳阿”，即升起了。一个月站在我们所说的时刻升起时，与它相对、称为它的“拉齐布”（守望者）的那一站，即从它数起的第十四站，正在那一刻沉落，这称为它的“坠落”。每一站之升与下一站之升之间约隔十三天，只是大约而非恰好，因为诸站的星并非都是同一星等，它们的纬度也不相等、方向也不一致。“安瓦”这个名称用于雨水，雨的时节归于清晨在西方沉落的那一站的坠落；“巴瓦里赫”这个名称用于风，在雨季之外，风归于清晨从光线下露出来的那一站的升起。这在阿拉伯人的地方是成立的，因为那里有雨季；但在相隔遥远的地方，空气中的事情各不相同，甚至在相邻而地势不同的地方，如海边与平原、低地与高地，也各不相同。

§168. What is the Milky Way?

第一百六十八问　何谓银河？

It is a collection of many patches of the kind of the nebulous stars, the whole lying approximately on the circumference of a great circle that passes through Gemini and Sagittarius, although it is dense in some places and thin in others, narrow in some and broad in others, and sometimes it branches so as to have forks. Aristotle held that it arises in the air from smoky vapour, opposite many stars gathered there, just as haloes and comets arise in the air opposite them.

它是许多斑块的集合，属于云状之星一类，整体大致落在一个经过双子与射手的大圆的圆周上，只是有的地方密、有的地方稀，有的地方窄、有的地方宽，有时还分出枝杈，成为有岔的样子。亚里士多德认为它是在空气中由烟状的蒸汽生成的，正对着聚集在那里的许多星，就像晕与彗星在空气中正对着星而生成一样。

§169. What are 'in the order of the signs' and 'against the order'?

第一百六十九问　何谓“顺星座次序”与“逆星座次序”？

When you go from a sign to the one that follows it towards the east, for example among the signs from Aries to Taurus, then Gemini, then Cancer, and among the mansions from al-Sharaṭān to al-Buṭayn, then al-Thurayyā, then al-Dabarān, that is the order of the signs. If you go among the signs from Aries to Pisces, then Aquarius, then Capricorn, and among the mansions from al-Sharaṭān to Baṭn al-Ḥūt, then the Hind Fargh, then the Fore [corrected: MS has the Fore, then the Hind], that is against the order of the signs. It is understood that this is meant with reference to the second, eastward motion. 'Preceding' and 'following', however, are judged by the first, westward motion: the preceding among the stars is what lies towards the west, which is against the order, and the following is what lies towards the east, which is the order.

当你从一个星座走到向东紧随其后的那个星座，例如星座中从白羊到金牛、再到双子、再到巨蟹，月站中从谢拉坦到布泰因、再到苏莱雅、再到代伯兰，这就是顺星座次序。如果你在星座中从白羊走到双鱼、再到水瓶、再到摩羯，在月站中从谢拉坦走到鱼腹、再到后法尔格、再到前法尔格〔抄本作“前法尔格，再到后法尔格”，据文义改正〕，这就是逆星座次序。须知这是就第二种运动、即向东的运动而言的。至于“在前”与“在后”，则按第一种运动、即向西的运动来判定：星之中在前的，是位于西边的，也就是逆次序一方；在后的，是位于东边的，也就是顺次序一方。

§170. What are the northern and the southern signs and mansions?

第一百七十问　何谓北方与南方的星座和月站？

The northern signs are six, namely Aries, Taurus, Gemini, Cancer, Leo and Virgo, because in them the zodiac lies north of the equator; the remaining six are the southern. Of the mansions, fourteen are northern, namely those that fall in the northern signs, from the beginning of al-Sharaṭān to the end of al-Simāk; the remaining fourteen are the southern.

北方星座有六个，即白羊、金牛、双子、巨蟹、狮子、处女，因为在这些星座里黄道位于赤道之北；其余六个是南方星座。月站之中，十四个是北方的，即落在北方星座里的那些，从谢拉坦之首到西马克之末；其余十四个是南方的。

§171. What is the parecliptic orb?

第一百七十一问　何谓拟黄道圈？

When the plane of the zodiac cuts the spheres of the planets, its cutting of each of them produces a circle parallel to the zodiac, which is the parecliptic orb of the planet of that sphere. It is called parecliptic (mumaththal, 'made like') with reference to the orb of the signs because it is parallel to it and in its plane; it is therefore divided by its divisions and fixed in all its states, because of the likeness between them.

当黄道的平面切割诸行星的天球时，它在每一个天球上都切出一个与黄道平行的圆，这就是那个天球所属行星的拟黄道圈。它是就黄道之圈而称为“仿造的”，因为它与黄道平行、又在黄道的平面上；所以它按黄道的分度来划分，在一切状态上都固定不变，这是由于两者相似。

§172. What is the apogee of the Sun?

第一百七十二问　何谓太阳的远地点？

The apogee is the highest place the Sun reaches in its sphere. For it moves not on the circumference of its parecliptic orb but on the circumference of another orb, which lies in its plane and whose centre is outside its centre, with the earth inside it. Necessarily, then, one point of it is the nearest of all its points to the centre of the earth, that is, the centre of the world, and the point opposite it is the farthest from it. The far point is called in Indian awj, which is derived from 'height', and likewise it is called in Greek afjūn, that is, the farthest distance; it is the summit of that eccentric orb, which is called the apogee orb. The near point is called in Greek afrījiyūn, that is, the nearest distance, which is the perigee of that orb. Inevitably there is in it a distance midway between the two distances mentioned, falling short of the farthest and exceeding the nearest by one and the same amount; this is what is called the mean distance. This is the figure of the eccentric apogee orb.

远地点是太阳在它的天球中所到的最高之处。因为太阳不是在它的拟黄道圈的圆周上运行，而是在另一个圈的圆周上运行；这个圈在拟黄道圈的平面上，圆心在拟黄道圈的圆心之外，大地在它里面。因此它必定有一点，是它所有的点中离大地中心、即世界中心最近的，与之相对的一点则离世界中心最远。远的那一点，印度语称为“奥季”，是从“高”一词派生的；希腊语同样称为“阿弗容”，意思是最远的距离；它是那个偏心圈的顶端，这个圈称为远地点圈。近的那一点，希腊语称为“阿弗里吉云”，意思是最近的距离，就是那个圈的近地点。在上述两个距离之间，必然有一个居中的距离，比最远者少、比最近者多，少与多是同一个量，这就是所谓平均距离。这是偏心的远地点圈的图。

§173. What is the mean position of the Sun?

第一百七十三问　何谓太阳的平位置？

The Sun moves with varying motions, going fast at one time and slowly at another, and between the speed and the slowness there is inevitably a mean, uniform motion, by which its course over periods of time is measured. This motion takes place on the circumference of the apogee orb, and the arc on it from the point facing the head of Aries in the parecliptic orb up to the body of the Sun is called its mean position. The mean portion of the Sun is the Sun's distance in the eccentric orb from the point of the apogee; therefore, when the distance of the apogee from the beginning of Aries is subtracted from the mean position of the Sun, this portion remains.

太阳以不均的运动运行，时而快、时而慢，在快与慢之间必然有一个平均而均匀的运动，用它来度量太阳在各段时间中的行程。这一运动发生在远地点圈的圆周上；在这个圈上，从正对拟黄道圈中白羊之首的那一点到太阳本体的弧，称为太阳的平位置。太阳的平均份，是太阳在偏心圈中距远地点之点的距离；因此，从太阳的平位置中减去远地点距白羊起点的距离，剩下的就是这一份。