February 20, 1896J 



NA rURE 



369 



He accounts for the idea of a long period of rotation 

 liaving been and still being upheld, on the ground that 

 lietween 320' and 1 50° longitude there are several spots 

 which are somewhat alike, six of which lie in a north and 

 south direction, and two in higher latitudes in an east 

 and west direction. 



For this reason, if an observer does not steadily watch 

 the planet from morning till evening every day, but 

 simply makes an occasional observation, he can then 

 easily mistake one spot for another, and imagine that he 

 is observing the same one when he is really observing 

 another, and thus conclude that no apparent motion of 

 the spot is noticeable. 



Whether this be so or not is, however, the question, 

 but one does not feel quite at liberty to state definitely 

 that therein lies the cause of Schiaparelli's, Tacchini's, 

 &c., deductions of a long period, for certainly they must 

 have convinced themselves thoroughly that such a rapid 

 rotation, which according to Brenner is so apparent, was 

 nevertheless to them very difficult of observation before 

 they committed themselves to definite statements. 



The following, but somewhat incomplete, list gives 

 some idea of the views held by observers regarding the 

 time of rotation of the planet under discussion. Column I. 

 gives the names of those who advocate the short period 

 of about 24 hours ; column II., with one exception, 

 those who are inclined to the period of, roughly, 225 days, 

 and column III., those who are doubtful. The dates 

 against sonie of the names refer to the times at which 

 the respective observations were made. 



I. II. * III. 



Short periotl. Long period. Doubtful. 



D. Cassini (1667) Bianchini (i727)>24'' Herschel, Sir W. 



J. Cassini (1730?) Schiaparelli Beer and Madler 



Schroter (1788-93) CeruUi I1833-36) 



De Vico (i840.'>) Tacchini 



Trouvelot (1877-91) Mascari 

 Leo Brenner 

 Stanley Williams 



During the first few months of this year the planet 

 will be a morning star. From the middle of January to 

 the middle of May, her time of rising before the sun 

 diminishes from three hours to half an hour, her apparent 

 diameter decreasing during this time from 16" to 10". 

 After August she will become an evening star, her 

 apparent distance from the sun increasing. In the 

 middle of November she will set one hour and a half, 

 and towards the end of December three hours, after 

 the sun ; her apparent diameter at this latter epoch 

 being 15". W. J S. L. 



THE SEEBOHM COLLECTION. 

 'X*HE British Museum has always owed much to the 

 ■'■ generosity of private donors, and this has been ex- 

 ceptionally true in the case of the collection of birds, 

 which is now the finest in the whole world. It is difficult 

 for ornithologists of the present day to imagine what the 

 collection was like five-and-twenty years ago in its old 

 quarters at Bloomsbury. Its principal value then con- 

 sisted of the type-specimens which it had received from 

 the earlier voyages, and the celebrated Nepalese collection 

 of .Mr. Brian Hodgson ; but the great series of Australian 

 birds obtained by John Gould had been allowed to go to 

 Philadelphia, apparently without a protest from any 

 public body in England, and to the great regret of Gould 

 himself He had offered the collection to the nation on 

 reasonable terms, which were afterwards eagerly accepted 

 by Dr. Edward Wilson, who transferred the whole series, 

 with its priceless types, to Philadelphia. 



The birds' skins in past years were kept in an under- 

 ground vault, in wooden boxes, so that if any particular 

 specimen was wanted by a student, the whole lot had 

 NO. 1373. VOL. 53] 



often to be turned out on the table, to render possible a 

 search for the skin required. The time thus wasted was 

 considerable, the damage to the specimens enormous, as 

 they were heaped one upon another in the boxes, and 

 every skin became more or less ruffled and spoilt as time 

 went on. As regards the mounted collection, the absurd 

 idea obtained that the public liked to see all the rare 

 birds, and thus all the valuable types and priceless 

 specimens were stuffisd and exhibited, there to wither with 

 the dust and exposure to light, and decay with age. 

 Many specimens of great value; known to have been in 

 the collection of the British Museum at the beginning of 

 the century, are now no longer to be found there ; they 

 have doubtless fallen to pieces from decay, and have been 

 thrown away. Even with the utmost care, I find it 

 difficult now to preserve some of the old Montagu 

 collection, the skins never having been properly pre- 

 served, and having been mounted with most of the bones 

 inside them. In this way also were preserved the 

 specimens of Captain Cook's voyage, most of which 

 have vanished since the time that Latham described 

 them, and they have doubtless crumbled to pieces. 



It is quite certain, therefore, that twenty-five years ago 

 the collection of birds in the British Museum was of 

 small repute, and probably did not exceed 40,000 speci- 

 mens. Little encouragement was given to travellers to 

 help the national collection, and, excepting in the case 

 of the Antarctic Expedition, and a i&w of the same kind, 

 the specimens received from explorers on sea and land 

 were few and far between. The best series were in the 

 hands of private collectors. Thus, for the study of 

 Palaearctic ornithology, students visited my collection and 

 that of Mr. H. E. Dresser, or that of Mr. Henry 

 Seebohm, already then commencing to loom large. For 

 Ethiopian birds, my own collection and that of Captain 

 Shelley were always available for the purposes of study, 

 and far exceeded that of the British Museum in number 

 of specimens. For Indian birds, that of the late 

 Marquis of Tweeddale was the one generally consulted, 

 and in India the influence of Mr. Hume was at work, and 

 his collection was already assuming large proportions. 

 The collection formed by the late Consul Swinhoe was 

 the best as regarded Chinese birds, and Dr. A. R. Wallace 

 still retained in his hands the chief set of the specimens 

 obtained by him during his travels in the Malay Archi- 

 pelago, with all the types. The best collection of 

 Australian birds was that in the possession of Messrs. 

 Salvin and Godman, though Mr. Gould had a large 

 number of valuable specimens, gathered together during 

 the previous thirty years, since the sale of his original 

 collection. As regards American birds, the absolute 

 dearth of species in the national collection can be 

 estimated from a glance at the late George Robert 

 Gray's "Hand-list of Birds," published in 1869-71, then 

 the authentic record of what the Museum possessed, 

 where genus after genus is scantily represented, and the 

 series of species is lamentably defective. With regard 

 to those of the Neotropical region, no great Museum, in 

 the year 1872, probably stood at a greater disadvantage 

 than the British Museum. The majority of the types of 

 American Passeres were in the collection of Dr. P. L. 

 Sclater, and, for a general series, nothing in Europe could 

 surpass that of the Salvin-Godman cabinet. 



In 1896 it is interesting to note the present location of 

 the above-mentioned private collections. They are all 

 in the British Museum. With the acquisition of the 

 Wallace collection in 1874, commenced that era of 

 improvement in the ornithological collection which has 

 steadily progressed, and is still progressing at the pre- 

 sent day. The Gould, Sclater, Shelley, and Sharpe 

 collections, with many others of greater or less import- 

 ance, have passed into the hands of the Trustees. Then 

 came, in 1885 the, magnificent donation of Mr. Allan 

 Hume, followed by that of the Tweeddale collection 



