NA TURE 



[April 21, 1887 



p. 240). Yet not the gods themselves, in Homer's time, 

 were aware of such a guide. It must be remembered, 

 however, that the axis of the earth's rotation pointed, 

 2800 years ago, towards a considerably different part of 

 the heavens from that now met by its imaginary pro- 

 longation. The precession of the equino.xes has been at 

 work in the interval, slowly but unremittingly shifting the 

 situation of this point among the stars. Some 600 years 

 before the Great Pyramid was built, it was marked by the 

 close vicinity of the brightest star in the Dragon. But 

 this in the course of ages was left behind by the onward- 

 travelling pole, and further ages elapsed before the star at 

 the tip of the Little Bear's tail approached its present 

 position. Thus the entire millennium before the Christian 

 era may count for an interregnum as regards Pole-stars. 

 Alpha Draconis had ceased to e.\ercise that office ; Al- 

 ruccabah had not yet assumed it. 



The most ancient of all the constellations is probably 

 that which Homer distinguishes as never-setting (it then 

 lay much nearer to the pole than it now does). In his 

 time, as in ours, it went by two appellations — the Bear 

 and the Wain. Homer's Bear, however, included the 

 same seven bright stars constituting the Wain, and no 

 more ; whereas our Great Bear stretches over a sky-space 

 of which the Wain is only a small part, three of the 

 striding monster's far-apart paws being marked by the 

 three pairs of stars known to the Arabs as the " gazelle's 

 springs." How this extension came about, we can only 

 conjecture ; but there is evidence that it was fairly 

 well established when Aratus wrote his description of the 

 constellations. Aratus, however, copied Eudoxus, and 

 Eudoxus used observations made — doubtless by Accad 

 or Chaldean astrologers — above 2000 B.C.' We infer, 

 then, that the Babylonian Bear was no other than the 

 modern Ursa Major. 



But the primitive asterism— the Seven Rishis of the 

 old Hindus, the Septem Triones of the Latins, the Ark- 

 tos of Homer — included no more than seven stars. And 

 this is important as regards the origin of the name. For 

 it is impossible to suppose a likeness to any animal 

 suggested by the more restricted group. Scarcely the 

 acquiescent fancy of Polonius could find it "backed like 

 a weasel," or " very like a whale." Yet a weasel or a 

 whale would match the figure equally well with, or better 

 than, a bear. Probably the growing sense of incongruity 

 between the name and the object it signified may have 

 induced the attempt to soften it down by gathering a 

 number of additional stars into a group presenting a 

 distant resemblance to a four-legged monster. 



The name of the Bear, this initial difficulty notwith- 

 standing, is prehistoric and quasi-universal. It was 

 traditional amongst the American-Indian tribes, who, 

 however, sensible of the absurdity of attributing a con- 

 spicuous protruding tail to an animal almost destitute of 

 such an appendage, turned the three stars composing it 

 into three pursuing hunters. 



The same constellation figures, under a divinified 

 aspect, with the title OUnva, in the great Finnish epic, 

 the " Kalevala." Now, although there is no certainty as 

 to the original meaning of this word, which has no longer 

 a current application to any terrestrial object, it is impos- 

 sible not to be struck with its resemblance to the Iroquois 

 term Okoiuari, signifying " bear," both zoologically and 

 astronomically (Lafitau, op. cit., p. 236). The inference 

 seems justified that Otduui held the same two meanings, 

 and that the Finns knew the great northern constellation 

 by the name of the old Teutonic king of beasts. 



It was (as we have seen) similarly designated on the 

 banks of the Euphrates ; and a celestial she-bear, doubt- 

 fully referred to in the Rig- Veda, becomes the starting- 

 point of an explanatory legend in the Ramayana (De 

 Gubernatis, " Zoological Mythology," vol. ii. p. 109). 



* According to Mr. Proctor's calculation. See R. Brown, " Eridanus : 

 River and Constellation," p. 3. 



Thus, circling the globe from the valley of the Ganges 

 to the great lakes of the New World, we find ourselves 

 confronted with the same sign in the northern skies, the 

 relic of some primieval association of ideas, long since 

 extinct. 



Extinct even in Homer's time. For the myth of Cal- 

 listo (first recorded in a lost work by Hesiod) was a 

 subsequent invention — an effect, not a cause — a mere 

 embroidery of Hellenic fancy over a linguistic fact, the 

 true origin of which was lost in the mists of antiquity. 



There is, on the other hand, no difficulty in understand- 

 ing how the Seven Stars obtained their second title of the 

 Wain, or Plough, or Bier. Here we have a plain case of 

 imitative name-giving — a suggestion by resemblance 

 almost as direct as that which established in our skies a 

 Triangle and a Northern Crown. Curiously enough, the 

 individual appellations still current for the stars of the 

 Plough, include a reminiscence of each system of nomen- 

 clature — the legendary and the imitative. The brightest 

 of the seven, a Ursae Majoris, the Pointer nearest 

 the Pole, is designated Dubhc, signifying, in Arabic, 

 " bear " ; while the title Benctnasch — equivalent to BeiiAt- 

 cn-Nasch, " daughters of the bier "—of the furthest star 

 in the plough-handle, perpetuates the lugubrious fancy, 

 native in Arabia, by which the group figures as a corpse 

 attended by three mourners. A. M. Clerk E 



[I'o be continued.) 



RAINBAND OBSERVATIONS AT THE BEN 

 NEVIS OBSERVATORY 



RAINBAND spectroscopy is one of the extra subjects 

 taken up at the Ben Nevis Observatory, along with 

 the usual meteorological routine. At every hour, when 

 there is sufficient light, the intensity of the rainband is 

 observed and recorded, and now, the mean daily rain- 

 band forms one of the items in the Ben Nevis weather 

 report in the daily newspapers. The scale in use is prac- 

 tically the same as that used by Dr. Mill, of the Granton 

 Marine Station, and described by him in a paper to the 

 Royal Society of Edinburgh (Proc. R.S.E , 1882-84). 

 This scale is in the spectrum itself — a great convenience 

 — being the Fraunhofer lines E, b, and F of the solar 

 spectrum. After a preliminary set of observations had 

 been made, in various types of weather, for the purpose 

 of determining the relative intensity of these lines, a 

 numerical value was given to each, namely, to E, 2 ; to b, 

 4 ; and to F, 7. After a little practice, it is quite easy to 

 estimate the values less than 2, which often occur, and 

 the values above 7, which very seldom occur. With this 

 scale, the intensity or darkness of the rainband and D 

 line taken together is compared, and the numerical value 

 of its scale- equivalent entered in the register. The 

 instrument used is one of Hilger's rainband pocket 

 spectroscopes, and the part of the sky always observed is 

 between 30° and 40° above the south-western horizon. 



The results obtained in 1885 were communicated to the 

 Scottish Meteorological Society, and are published in their 

 Journal for 1 886 (see Nature, vol. xxxiii. p. 622). In 

 1886, over 3000 observations were made, and the relative 

 frequency with which each number of the scale was ob- 

 served will convey an idea of the intensity of the rain- 

 band on Ben Nevis. The percentage of observations of 

 each number is as follows : — 



Rainband o i 234567 



Percentage ... 24 31 27 8 7 i I i 



The mean of all the observations gives a rainband of 17. 

 Now at sea-level, according to Dr. Mill, the rainband is 

 seldom or never less than E, that is, than 2 on our scale. 

 Hence the mean rainband on the Ben is about equal to 

 the minimum at sea-level. About 80 per cent, of these 

 observations were made when the Ben was enveloped in 

 fog or mist. The only effect fog or mist has upon the 



