268 



NATURE 



\yan. 23, 1879 



"... white and aiure, laced 

 r* With blue of heaven's own tint. " 



Cymbeline, 11. sc. 2. 



" Whose ranks of blue veins." — Lucrece. 

 " Those blue-veined violets."— yemts aiui Adonis. 

 " Where fires thou find'st unraked, and hearths unswept 

 There pinch the maids as blue as bilberry." 



Merry IVivcs of Windsor, v. sc. 5. 



", And Hony soit qui mcily peiise write 

 In emerald tufts, flowers purple, blue, and white, 

 Like sapphire, pearl, and rich embroidery." — Ibid., v. sc. 5. 



Here there is no confusion. The comparisons are exact and 

 beautiful. Again we have — 



" When wheat is green, when hawthorn buds appear." 



Midsummer Night's Dream, i. sc. i. 



The season indicated shows there was no confusion between 

 green and brown. 



We must not forget the well-known song — 



" When daisies pied and violets blue. 

 And lady-smocks all silver white, 

 And cuckoo-buds of yellow hue 

 Do paint the meadows with delight." 



Love's Labour Lost, v. sc. 2. 



And. to conclude our comparisons of green and blue — 



"... I will rob Tellu.<! of her weeds 

 To strew thy green with fl nvers: the yellows, blues. 

 The purple violets, and marigolds, 

 Shall as a chaplet hang upon thy grave." 



Pericles, iv. sc. 1. 



Returning to the colour of eyes. Shakespeare not only knew a 

 blue eye, but could discriminate, and appreciate the beauty of a 

 grey eye — ^a shade which often does duty for blue. The lovely 

 rivals Julia and Sylvia are so endowed — 



" Her eyes are grey as glass — and so are mine." 



Two Gentlemen 0/ Verona, iv. sc. 4. 



"... Thisbe, a grey eye or so." 



Ro7neo and yuliel, ii. sc. 4. 



I think the above quotations afford good proof of the poet's 

 correctness of colouring with regard to green and blue. It is 

 true that he occasionally uses a small degree of licence with 

 purple and blue, in the case of violets ; but clearly not from 

 ■unconsciousness of the difference. I cannot remember any 

 instance where he confuses green with blue except purposely and 

 humorously. 



In the use of other colours Shakespeare is in most instances I 

 am acquainted with equally true to nature. To give examples 

 would occupy too much space ; but if there are exceptions I 

 have no doubt that your correspondents — now that the matter is 

 broached — ^will be able to furnish them. 



Sligo, January 10 EDWARD T. Hardman 



Intellect in Brutes 



The following incident may interest some of the readeis of 

 Nature, as affording evidence of the possession and exercise of 

 reasoning power by a brute. During the present frost the 

 window-sills of my dra\^ ing-room are supplied with bread for 

 the benefit of the birds, who, finding food there, are constantly 

 fluttering about the windows. One day a large water-rat was 

 seen on the Mdndow-sill, helping himself to the bread. In order 

 to reach the window he. had to chmb to a height of about thirteen 

 feet : this. he did by the help of a-shrub trained against the wall. 

 Neither instinct nor experience will easily account foi- his conduct : 

 since he never found food there before. If neither experience 

 nor instinct, what save reason led him ? His action seems to 

 have been the result of no small observation and reasoning. He 

 seems to have said to himself — I observe the birds are thronging 

 that window all day ; they would not be there for nought ; it 

 niay be they find there something to eat : if so, perhaps I too 

 •might find Uiere something which I should like.- I shall try. 



Bardsea ...... Edward Geoghegan 



OUR ASTRONOMICAL COLUMN 



Olbers' Comet of 1815. — On March 6, iSiS^rOlbers 

 discovered a- small cornet at' Bremeny in abdat 4^" right 

 ascension, and 32° nbrt;b'"Heclination, or between Perseus 

 and Musca ;' it had an iU-^efined nucleus and was not 



visible without telescopic aid. The first parabolic elements 

 were calculated by Olbers himself, and he was followed 

 by Bessel, Gauss, Triesnecker and others in the deter- 

 mination of similar orbits. Ephemerides founded upon 

 them showed that the comet would be observable for a 

 considerable period, and as the result proved observers 

 were not negligent of this circumstance. Gauss, writing 

 to Bode on April 24, alludes to the long visibility of the 

 comet, and the probability that elliptical elements would 

 be found, but this remark apparently was merely intended 

 to imply that the grasp which a long course of observa- 

 tion would afford upon the orbit, might lead to an ellipse, 

 not that Gauss had remarked any sensible deviation from 

 parabolic motion ; indeed he mentions that he had not 

 then reduced his April observations. The first detection 

 of the inadequacy of the parabola to represent accurately 

 the comet's course, is due to Bessel: he had calculated 

 parabolic elements from observations on March 11, 

 April II, and May 20, which, while agreeing well with 

 the positions employed, gave the right ascensions sensibly 

 too small from March 1 1 to April 1 1, and between April 

 1 1 and May 20, as decidedly too great, even to as much 

 as 4', and on May 26, the calculation was again many 

 minutes in defect; these differences naturally induced 

 Bessel to relinquish the parabolic hypothesis, and after 

 some disappointment from the failure of the first method 

 he employed, he communicated to Olbers on June 23 the 

 elements of an elliptical orbit, in which the period of 

 revolution was a little over 73 years. At the end of June 

 Gauss deduced an ellipse with a period of 77 years, and 

 soon afterwards Nicolai, then assistant to von Lindenau 

 at Gotha, added a further confirmation of the elliptical 

 character of the orbit, assigning a revolution of 72^ years. 

 On July 22, being in possession of observations to the 

 middle of the month, Bessel improved upon his first cal- 

 culation, and now found an ellipse with a period of 73 "8968 

 years, which was made the foundation for his subsequent 

 investigations, of which we have presently to speak. 

 Thus was the periodicity of the comet established, and 

 Bessel, after remarking upon the importance of the addi- 

 tion to the system (at that time Haile/s comet was the 

 only one that could be considered certainly periodical) he 

 proposed that it should bear the name of its discoverer — 

 Olbers. 



Besides a long series of observations taken by Olbers 

 himself, the comet was observed by Gauss at Gottingen, 

 Bessel at Konigsberg, Triesnecker at Vienna, Struve at 

 Dorpat, Oriani at Milan, Lindenau at Gotha, Maskelyne 

 at Greenwich, and Bouvard at Paris. Its distance from 

 the earth continued pretty nearly constant (about i'4S) 

 during the greater portion of the time it was visible, and 

 at no period was it a conspicuous object ; its nucleus was 

 pretty bright at the beginning of May, and it then had a 

 tail about 1° in length. 



On the disappearance of the comet Bessel collected the 

 observations which extended to August 25, the last having 

 been made by Gauss at Gottingen ; indeed, he was the 

 only observer after July 25. He then commenced the 

 work which is incorporated in his great memoir upon this 

 comet, published in " Abhandlungen der koniglichen 

 Akademie der Wissenschaften in Berlin, 18 12-13," a 

 volume which was not published until 1816. He formed 

 ten normal positions, in which all the observations appear 

 to be brought to bear, excepting those at Greenwich and 

 Paris, which were doubtless unknown to him. He cor- 

 rects these normals for the effect of perturbations from 

 the action of Venus, the Earth, Mars, Jupiter, and 

 Saturn, during the comet's visibility, and by a fine series 

 of observations of the sun at Konigsberg between March 8 

 and August 29, 1815, he appHes corrections to the sun's 

 places obtained from Carhni's first tables. Equations of 

 condition were then formed and solved on the method of 

 least squares, and thus the following definitive elements of 

 the comet's orbit in 181 5 were obtained : — 



