Chapter 7: Planetary Conjunctions

Of the star-planets there take place, with one another, encounter ( yuddha ) and conjunction ( samdgama ) ; with the moon, conjunction (samdgama ) ; with the sun, heliacal setting (astamana). The “ star-planets ” ( tdragraha ) are, of course, the five lesser planets, exclusive of the sun and moon. Their conjunctions with one another and with the moon, with the asterisms (naksJiatra), and with the sun, are the subjects of this and the two following chapters. For the general idea of “ conjunction ” various terms are indifferently employed in this chapter, as samdgama, “ coming together,” samyoga, ” conjunction/’ yoga , “ junction ” (in viii. 14, also, melaka , “ meeting ”) : the word yuti, “ union,” which is constantly used in the same sense by the commentary, and which enters into the title of the chapter, graha- yutyadhikdra, does not occur anywhere in ihe text. The word which we translate ” encounter,” yuddha , means literally “ war, conflict.” Verses 18-20, and verse 22, below, give distinctive definitions of some of the different kinds of encounter and conjunction.

When the longitude of the swift-moving planet is greater than that of the slow one, the conjunction ( samyoga ) is past ;

When the longitude of the one moving eastward is greater, the conjunction ( samdgama ) is past ; but when that of the one that is retrograding is greater, it is to come. Multiply the distance in longitude of the planets, in minutes, by the minutes of daily motion of each,

And divide the products by the difference of daily motions, if both are moving with direct, or both with retrograde, motion : if one is retrograding, divide by the sum of daily motions.

The quotient, in minutes, etc., is to be subtracted when the conjunction is past, and added when it is to come : if the two are retrograding, the contrary : if one is retrograding, the quotients are additive and subtractive respectively.

Thus the two planets, situated in the zodiac, are made to be of equal longitude, to minutes. Divide in like manner the distance in longitude, and a quotient is obtained which is the time, in days, etc. The object of this process is to determine where and when the two planets of which it is desired to calculate the conjunction will have the same longitude. The directions given in the text are in the main so clear as hardly to require explication. The longitude and the rate of motion of the two planets in question is supposed to have been found for some time not far removed from that of their conjunction. Then, in determining whether the conjunction is past or to come, and at what distance, in arc and in time, three separate cases require to be taken into account — when both are advancing, when both are retrograding, and w hen one is advancing and the other retrograding. In the two former cases, the planets are approaching or receding from one another by the difference of their daily motions; in the latter, by the sum of their daily motions. The point of conjunction will be found by the following proportion : as the daily rate at which the tw r o are approaching or receding from each other is to their distance in longitude, so is the daily motion of each one to the distance which it will have to move before, or which it has moved since, the con- junction in longitude. The time, again, elapsed or to elapse between the given moment and that of the conjunction, will be found by dividing the

Haring calculated the measure of the day and night, and likewise the latitude (vikshepa), in minutes ; having determined the meridian-distance ( nata ) and altitude (unnata), in time, according to the corresponding orient ecliptic-point (lagna ) —

Multiply the latitude by the equinoctial shadow, and divide by twelve; the quotient multiply by the meridian-distance in nadis, and divide by the corresponding ball-day :

The result, when latitude is north, is subtractive in the eastern hemisphere, and additive in the western ; when latitude

Multiply the minutes of latitude by the degrees of declination of the position of the planet increased by three signs : the result, in seconds ( vikald ), is additive or subtractive, according as declination and latitude are of unlike or like direction.

In calculating the conjunction (yoga) of a planet and an asterism (nakshatra), in determining the setting and rising of a planet, and in finding the elevation of the moon’s cusps, this operation for apparent longitude (drkkarman) is first prescribed.

Calculate again the longitudes of the two planets for the determined time, and from these their latitudes : when the latter are of the same direction, take -their difference; otherwise, their sum : the result is the interval of the planets. The whole operation for determining the point on the ecliptic to which a planet, having a given latitude, will be referred by a secondary to the prime vertical, is called its drkkarman. Both parts of this com- pound we have had before — the latter, signifying “ operation, process of calculation,” in ii. 37, 42, etc. — for the former, see the notes to iii. 28- 34, and v. 5-6: here we are to understand it as signifying the “ apparent longitude ” of a planet, when referred to the ecliptic in the manner stated, as distinguished from its true or actual longitude, reckoned in the usual way: we accordingly translate the whole term, as in verse 11, “ operation for apparent longitude.” The operation, like the somewhat analogous one by which the ecliptic-deflection ( valana ) is determined (see above, iv. 24-25), consists of two separate processes, which receive in the commentary distinct names, corresponding with those applied to the two parts of the process for calculating the deflection. The whole subject may be illustrated by reference to the next figure (Big. 28). This represents the projection of a part of the sphere upon a horizontal plane, N and E being the north and east points of the horizon, and Z the zenith. Let CL be the position of the ecliptic at the moment of conjunction in longitude, C being the orient ecliptic-point (lagna); and let M be the point at which the conjunction in longitude of the two planets S and V, each upon its parallel of celestial latitude, cl and c'i', and having latitude equal to SM and VM respectively, will take place. Through Y and S draw secondaries to the prime vertical, NV and NS, meeting the ecliptic in v and s : these latter are the points of apparent longitude of the two planets, which are still removed from a tr,ue conjunction by the distance vs : in order to the ascertainment of the time of that true conjunction, it is desired to know the positions of v and 8, or their respective distances from M. From P, the pole of the equator, draw

The diameters upon the moon’s orbit of Mars, Saturn; Mercury, and Jupiter, are declared to be thirty, increased suc- cessively by half the half ; that of Venus is sixty.

These, divided by the sum of radius and the fourth hypothenuse, multiplied by two, and again multiplied by radius, are the respective corrected ( sphuta ) diameters : divided by fifteen, they are the measures (mdna) in minutes. We have seen above, in connection with the calculation of eclipses (iv. 2-5), that the diameters of the sun, moon, and shadow had to be reduced, for measurement in minutes, to the moon's mean distance, at which fifteen yojanas make a minute of arc. Here we find the dimensions of the five lesser planets, when at their mean distances from the earth, stated only in the form of the portion of the moon’s mean orbit covered by them, their absolute size being left undetermined. We add them below, in a tabular form, both in yojanas and as reduced to minutes, appending also the corresponding estimates of Tycho Brahe (which we take from

Exhibit, upon the shadow-ground, the planet at the extremity of its shadow reversed : it is viewed at the apex of the gnomon in its mirror. As a practical test of the accuracy of his calculations, or as a con- vincing proof to the pupil or other person of his knowledge and skill, the teacher is heje directed to set up a gnomon upon ground properly prepared for exhibiting the shadow, and to calculate and lay off from the base eff the gnomon, but in the opposite to the true direction, the shadow which a planet would cast at a given time; upon placing, then, a horizontal mirror at the extremity of the shadow, the reflected image of the planet’s disk will be seen in it at the given time by an eye placed' at the apex of the gnomon. The principle of the experiment is clearly correct, and the rules and processes taught in the second and third chapters afford the means of carrying it out, since from them the shadow which any star would cast, had it light enough, may be as readily determined as that which the sun actually casts. As no case of precisely this character has hitherto been

Take two gnomons, live cubits (hasta) in height, stationed according to the variation of direction, separated by the interval of the two planets, and buried at the base one cubit.

Then fix the two hypothenuses of the shadow, passing from the extremity of the shadow through the apex of each gnomon : and, to a person situated at the point of union of the extremities of the shadow and hypothenuse, exhibit.

The two planets in the sky, situated at the apex each of its own gnomon, and arrived at a coincidence of observed place (d?Q). . . . This is a proceeding of much the same character with that which forms the subject of the preceding passage. In order to make apprehen- sible, by observation, the conjunction of two planets, as calculated by the methods of this chapter, two gnomons, of about the height of a man, are $et up. At what distance and direction from one another they are to be fixed is not clearly shown. The commentator interprets the expression “ interval of the two planets ” (v. 16), to mean their distance in minutes on the secondary to the prime vertical, as ascertained according to verse 12, above, reduced to digits by the method taught in iv. 26 whiie, by “ according to the variation of direction,” he would understand merely, in the direction from the observer of the hemisphere in which the planets at the moment of conjunction are situated. The latter phrase, however, as thus explained, seems utterly nugatory; nor do we see of what use it would be to make the north and south interval of the bases of the gnomons,

An encounter ( yuddha ) is called “ray-obliteration” (anquvimarda) when there is mutual mingling of rays : when the interval is less than a degree, the encounter is named “ dexter ” (apasavya) — if, in this case, one be faint ( anu ).

If the interval be more than a degree, it is “ conjunc- tion ” ( sanidqama ), if both are endued with power ( bala ). One that is vanquished (jita) in a dexter encounter ( apasavya yuddha ), one that is covered, faint (anu), destitute of brilliancy,

One that is rough, colorless, struck down ( vidhvasta ), situated to the south, is utterly vanquished ( vijita ). One situated to the north, having brilliancy, large, is victor ( jayin ) — and even in the south if powerful ( balin ).

Even when closely approached, if both are brilliant, it is * 4 conjunction ” (samdgama) : if the two are very small, and

Venus is generally victor, whether situated to the north or to the south. . . . ' In this passage, as inter in a whole chapter (chap, xi), we quit the proper domain of astronomy, and trench upon that of astrology. How- ever intimately connected the two sciences may be in practice, they are, in general, kept distinct in treatment — the Siddhantas, or astronomical text-books, furnishing, as in the present instance, only the scientific basis, the data and methods of calculation of the positions of the heavenly bodies, their eclipses, conjunctions, risings and settings, and the like, while the Sanhitas, Jatakas, Tajikas, etc., the astrological treatises, make the super- stitious applications of the science to the* explanation of the planetary influences, and their determination of human fates. Thus the celebrated astronomer, Varaha-mihira, besides his astronomies, composed separate astrological works, which are still extant, while the former have become lost. It is by no means impossible that these verses may be an interpola- tion into the original text of the Surya-Siddhanta. They form only a dis- connected fragment : it is not to be supposed that they contain a complete statement and definition of all the different kinds of conjunction recog- nized and distinguished by technical appellations; nor do they fully set forth the circumstances which determine the result of a hostile “ encounter” between two planets : while a detailed explanation of some of the distinc- tions indicated — as, for instance, when a planet is ” powerful ” or the contrary — could not be given without entering quite deeply into the subject of the Hindu astrology. This we do not regard ourselves as called upon to do here: indeed, it would not be possible to accomplish it satisfactorily without aid from original sources which are not accessible to us. We shall content ourselves with following the example of the commentator, who explains simply the sense and connection of the verses, as given in our translation, citing one or two parallel passages from works of kindred subject. We would only point out farther that it has been shown in the most satisfactory manner (as by Whish, in Trans. Lit. Soc. Madras, 1827; Weber, in his Indische Studien, ii. 236 etc.) that the older Hindu science of astrology, as represented by Varaha-mihira and others, reposes entirely upon the Greek, as its later forms depend also, in part, upon the Arab; the latter connection being indicated even in the common title of the more modern treatises, tajika, which comes from the Persian tazi “ Arab.” Weber gives (Ind. Stud. ii. 277 etc.) a translation of a passage from Varaha-mihira’s lesser treatise, which states in part the circumstances deter- mining the power ” of a planet in different situations, absolute or relative : partial explanations upon the same subject furnished to the translator in

Unto the good and evil fortune of men is tins system set forth : the planets move on upon their own paths, approaching one another at a distance.