May, 1001/ 



KNOWLEDGE. 



lo; 



Slight variations from the normal types, or sub- 

 divisions of the same, have so far been indicated by 

 placing lettei's after the four type numbers. 



The illustration, which shows not only the four types, 

 but their sequence, is that of a large sun-spot group 

 which first appeared on the sun on March 31, ISS4, 

 and lived for lOS days to July 17, passing the central 

 meridian five times. The five horizontal sections of the 

 plate correspond to the five rotations. The spot group 

 was born at the centre of the visible disc on March 31, 

 when it appeared as a few scattered dots, the first phase 

 or Type I. of our divisions. By April 3 it had reached 

 the phase, designated by Type II., when two main spots 

 predominated. Thus it continued until the oth, when the 

 train appeared between the two spots, corresponding to 

 Type III. On April Gth it was near the sun's western 

 limb which it passed on the 7th. At its return it was 

 first recorded on the 22nd, appearing on that date and 

 on the three following days as an elongated single 

 spot with a train of smaller companions. This phase is 

 represented by one of the subdivisions of Type IV. On 

 April 26th and the following day it had reverted to 

 Type II., and on the 2Sth, 29th, aiid 30th to Type I\., 

 subdivision '/. Thus it remained until it again passed 

 the western limb on May 4th. At its next two returns, 

 when it was followed during each of the thirteen days 

 that it was visible, it had become a single round spot, the 

 normal spot of Type IV. It will be noticed that during the 

 fourth appearance a sm.all subsidiary group formed to 

 the north of the original group, and that even in this 

 small outburst the two spot type is evident. At its fifth 

 appearance, when it was gradually disappearing, it had 

 resumed the phase which belongs to Type I. A closer 

 examination of the series of phases represented on the 

 plate will show many other interesting points, as 

 for instance the formation of tails to the leading spot 

 of the group, and the narrowing of the penumbra on the 

 side of the spot turned towards the sun's centre in ro- 

 tation the third, even before it had reached a position 

 near the limb where the effect of perspective would have 

 been apparent. The illustrations are drawn to a scale 

 of lOi inches to the solar diameter. 



In a subsequent paper the relation of faculae to sun- 

 spot groups will be dealt with. 



CONSTELLATION STUDIES. 



By E. Walter Maunder, f.r.a.s. 



v.— THE SCORPIOX AND THE SERPENT- 

 HOLDER. 



How many constellations did the original Chaldean 

 Zodiac contain, — eleven or twelve ? The question is a 

 very important one as bearing on the origin of the 

 Zodiac, since the twelvefold division is significant of 

 the ancients having determined the length of the year at 

 least approximately before the constellations were 

 mapped out. 



The assertion that the Chaldean Zodiac consisted 

 originally of only eleven constellations is made explicitly 

 by Servius the grammarian, in his commentary on the 

 works of Virgil. The latter in his address to the 

 Emperor Augustus, in the first Georgic, suggests that the 

 space which lies between the Virgin and the following 

 Claws, lies vacant for him ; " the glowing Scorpion 

 drawing back its arms and leaving for him a more than 

 ample space of sky." Our Greek authorities, however, 

 made the signs of the Zodiac twelve in number, but 



gave to one of the figures a double space; the Scorpion 

 occupying one sign with its body and another with its 

 outstretched Claws. Brown's explanation of this double 

 honour given to the poisonous reptile is very ingenious. 

 Quoting from Aratus. he points out the old legend of 

 how Orion was slain bj' a gigantic scorpion in punish- 

 ment for his attack upon Artemis : — 



" And great Orion, too, his (the Scorpion) advent fears. 

 Content thee, Artemis 1 A tale of old 

 TelU how the strong Orion seized thv robe 

 When he in Cliios, with his sturdy mnee 

 A hnntor, smote the beast to gain (Knopion's thanks. 

 But slie fortliwitli another monster bade — 

 Tlie .**c-c>rpion, liaving cleft the island's liills 

 In midst on either side : Tliis, huger still, 

 His greatne-<s smote and slew, sinee Artemis he chased. 

 And so 'tis saitl that, wlien the .Scorpion comes, 

 Orion flies to utmost end of i^arth." 



(Brown's Aratus.) 

 Orion, the most gorgeous of all the constellations, is, 

 according to this theory, a stellar representation of the 

 sun ; the Scorpion, on the other hand, represents the 

 night and the power of darkness. " As the huge size 

 of Orion, i.e., that of the sun as compared with the stars, 

 is always insisted on, so the scorpions of darkness are of 

 colossal size, infinitely greater than the Orion sun." The 

 gigantic size of the Scorpion, therefore, was insisted on 

 by bestowing on it a double portion of the Zodiac. 



Our present name for the seventh constellation of the 

 Zodiac, Libra the Balance, we owe to the Romans, Virgil 



writing in the first Georgic : 



" Libra die somnique pares ubi fecerit horas " 

 but we cannot now say how far back into antiquity the 

 symbol goes. Though as Aratus truly says, 



" Few are its stars for splendour and renown.'' 

 The constellation Libra can be readily found by an 

 alignment from Arcturus : — - 



" Where yon gaunt Bear disports a tail, seek .-Vlkaid at its tip. 

 From thence a ray athwart the space to south-south-east must dip; 

 And when Arcturus lias been passed prolong th' imagin'd line, 

 'Twill mark a star, a,s far again, the first in Libra's sign." 



Alpha Librae is an unlucky star as to its name ; 

 it really should be Zuben el Genubi, the southern claw ; 

 but it is often called Zuben el Chamali, the northern 

 claw, a title which clearly belongs to Beta Librae. 

 The star marks the ecliptic almost exactly, and it forms 

 a very pretty double to the opera-glass. 



Beta Librae, forming an equilateral triangle with 

 Alpha Librae and with Mu Virginis, is a star with a 

 markedly greenish colour, and interesting history. For 

 Eratosthenes calls it the brightest of all the stars in 

 the Scorpion, that is in the double constellation, and 

 Claudius Ptolemy gives it as equal with Antares. As 

 it is now a full magnitude fainter than Antares it must 

 have faded greatly. 



But passing on to the Scorpion proper, we come to 

 the finest region of the sky as seen in southern realms. 

 There is no difficulty in tracing out the Scorpion. Ant- 

 ares, its brightest gem, is almost exactly as far beyond 

 Spica as Spica is beyond Regulus; and Arcturus, Spica 

 and Antares, make up a magnificent right-angled tri- 

 angle, Spica marking the right angle. Antares stands 

 in a long and beautifully winding curve, made of bright 

 stars, which mark out the bo<ly and reverted sting of 

 the reptile; and fainter stars to right and left show 

 its legs. " There are few constellations," as Serviss 

 truly 'remarks, " which bear so close a resemblance to 

 the objects thev are named after, as Scorpio. It does 

 not require a very violent exercise of the imagination 



