104 



NATURE 



[December 5, 1901 



having a distinct dorsal stripe on the otherwise dun back, 

 and a welldeveloped forelock, while the muzzle, with the 

 exception of the nose ' (which is whitish), is said to be 

 black, and the tail, which appears to be haired to the 

 root, is rather short and bushy in winter. Moreover, the 

 colour of the tail and mane is said to be reddish-brown. 

 Nothing is stated with regard to the front of the legs 

 being black. 



So far as can be determined from this description, the 

 tarpan appears identical with Eguus caballus (of which it 

 is probably the ancestral form), which is certainly not 

 the case with E. przeioalskii. 



But another important point arises in connection with 

 the animal under consideration. Naturalists commonly 

 divide the existing species of Equus into two groups, the 

 one containing only the horse, and the other the asses 

 and zebras. Przewalskis horse will, however, clearly find 

 a place in the foriner group, and as this animal ap- 

 proximates in some respects to the kiang, which differs 

 from the African wild asses by its shorter ears, larger 

 hoofs (especially the front pair) and absence of a 

 shoulder-stripe and bars on the legs, I am inclined to 

 think that the horse, Przewalski's horse, and the kiang 

 (Asiatic wild ass) form one natural group, and the African 

 wild ass, quagga and zebras a.second. This 

 arrangement will harmonise with distribu- 

 tion much better than the old one. 



Taking the tarpan as the wild representa- 

 tive of the horse, it will be noticed that all 

 three members of the first group agree in the 

 general absence of the shoulder-stripe and of 

 dark markings on the leys. And the question 

 then arises, how is it that certain domestic- 

 ated horses (especially dun-coloured ponies 

 in the Punjab) show both these markings ? 

 Can it be owing to a cross with the .African 

 ass, or is it due to reversion to the common 

 ancestor of the equine genus? R. L. 



TYCHO BRAHE'S OBSERVATORY. 



IT was mentioned in a recent article on 

 the tercentenary of Tycho Brahe's death 

 (p. 6) that an account of excavations made 

 in the island of Ilveen has been published 

 by Prof. Charlier, of Lund.-' As Tycho's 

 observatory has thus again attracted atten- 

 tion, it may not be out of place to give a 

 short description of it as it was three hun- 

 dred years ago, and of the very few remains of it now 

 brought to light. 



Tycho's magnificent buildings were destroyed less 

 than twenty-two years after his death. In 1623 a mason 

 was paid for 60,000 bricks " which he had pulled down 

 and renovated from the old castle," and they were used 

 to build a new dwelling-house at a little distance, which 

 in its turn has disappeared within the last hundred 

 years. Apparently the peasants of the island helped 

 themselves to bricks and stones as much as they liked, 

 as part of the foundation-stone (laid by Tycho's friend 

 the French envoy, Charles de Danzay) was recently dis- 

 covered in the wall of an outhouse of a farm on the east 

 coast of the island, still showing part of the Latin in- 

 scription and the date 1576 August 8. When Picard 

 was sent over by the Paris Academy, in 1671, to deter- 

 mine the geographical position of Uraniborg, only the 

 foundations of the house and the greater part of the 

 ramparts surrounding it were still intact, while on the 



' The expression " nose " is .-i little ambiguous, but the figures do not 

 show a white mu/zle like that of /•:. przc-.valskit. 



" " UlRriifningarna af Tycho Brahe's observatorier p^tin Hven sommaren 

 igoi." Beskrifna af C. V. L. Charlier. 20 pp., 4to, with 3 plates. (Lund, 

 1901.) 



site of the observatory only a slight hollow in the ground 

 was noticeable. Picard did not trouble himself about 

 making excavations, and apparently everything was left 

 undisturbed until 1823, when the clergyman of the island, 

 Ekdahl, made careful excavations. At L'raniborg he 

 found the deep well which was under Tycho's kitchen 

 and still sup'plies the neighbourhood with excellent water, 

 while parts of the foundation-walls and some slight 

 remains of the laboratory (in the basement of the house) 

 were also unearthed. These must have been covered 

 over again, as nothing was visible on this spot until the 

 present year, when the same trifling ruins of Tycho's 

 beautiful residence were again laid bare ; but as nothing 

 of any scientific interest was found, we may at once pass 

 to the underground observatory, of which much more 

 distinct traces still remain. 



Uraniborg, the stately residence of Tycho Brahe, was 

 finished in 1 580 and contained four observing rooms, 

 two at the north and two at the south end of the building. 

 But already a year or two later a large meridian quadrant 

 was erected in one of the sitting-rooms, and very soon, as 

 the work increased, it was found that even with this 

 addition to the equipment more instruments were wanted. 

 In 1584 an observatory was therefore built on a low hill 



about a hundred feet south of the south corner of the 

 enclosure of Uraniborg and slightly to the east. This 

 observatory, of which we here give a view from the west 

 and a plan,' was called Stelkoburguni (Danish, Stjerne- 

 borg) ; in it the instruments were placed in three sub- 

 terranean rooms (C, ('. and r on the plan), of which only 

 the roofs rose above the ground, so that they were well 

 protected from the wind. The entrance was to the north, 

 and in the centre was a study, lighted by four small 

 windows just above the ground, and which could be 

 heated by a stove in a recess (at l'). while off it there was 

 an alcove with a bed where Tycho could rest during 

 cloudy intervals. In 1585 two other rooms for instru- 

 ments (l) and E) were added, but the floors of these 

 were almost on the level of the ground, probably 

 because he had found it inconvenient not to be able to 

 observe stars near the horizon from the three under- 

 ground rooms. The whole was surrounded by a low 

 wooden paling, forming a square with sides 57 feet long, 

 with semicircular bends at the middle of each side of 

 20 feet diameter, and stone piers were placed inside the 



' Taken from the writer's book, "Tycho Brahe," by permission of 

 Messrs. A. and C. Black. 



no'. 1675, VOL. 65] 



