Nov. 3, 1887] 



NATURE 



13 



picture the process as one not wholly dissimilar ; and 

 this is what in one place we tried to do ; with, however, 

 but poor success. 



I have said that an electric current need be nothing 

 more occult than is a charged sphere moving rapidly ; 

 and a good deal has been made out concerning currents 

 by minutely discussing all that happens in such a case. 

 But, even so, the problem is far from being a simple 

 one. One has to consider not only the obviously moving 

 charge, but also the opposite induced charge tied to it by 

 lines of force (or tubes of induction, as they are some- 

 times called), and we have this whole complicated system 

 in motion. And the effect of this motion is to set up a 

 new phenomenon in the medium altogether — a spinning 

 kind of motion that would not naturally have been ex- 

 pected ; whereby two similarly charged spheres in motion 

 repel one another less than when stationary, and may 

 even begin to attract, if moving fast enough ; whereby 

 also a relation arises between electricity and magnetism, 

 and the moving charged body deflects a compass needle. 

 Of which more in the next Part. Oliver J. Lodge. 

 ( To be continued^ ■ 



THE TWEEDDALE COLLECTION. 



'T*HE great collection of birds formed by the late 

 ■■■ Marquess of Tweeddale has now safely arrived in 

 London, and has been deposited in the Natural History 

 Museum at South Kensington. It is sufficient to say that 

 it equals in extent the valuable donation of American 

 birds presented by Mr. Osbert Salvin and Mr. F. Du Cane 

 Godman, numbering about 27,000 specimens ; and though 

 inferior in number of individual skins to the great Hume 

 collection, which reached the phenomenal number of 

 63,000 specimens, it is not inferior in interest to either of 

 these wonderful collections. Mr. Hume thoroughly 

 worked the territory of the British Asian Empire from 

 Scinde to Assam and Manipur, from Khatmandu to 

 Ceylon, and from Tenasserim to Singapore ; but to the 

 eastward of these countries the work had been continued 

 by other naturalists, and the results of their labours are 

 largely represented in the Tweeddale collection, which now 

 forms part of the British Museum. 



On the death of the late Marquess, his entire collection 

 and library were bequeathed by him to his nephew, 

 Capt. R. G. Wardlaw Ramsay, of Whitehill, a natu- 

 ralist of high promise and performance ; and in the 

 moment of satisfaction at receiving his magnificent dona- 

 tion one cannot help feeling great regret that the many 

 cares and duties mcident upon his succession to the 

 family estates at Whitehill have temporarily deprived 

 him of the leisure necessary for the working out of the 

 great collection left to him by his uncle. The facilities 

 for ornithological study, however, at the Natural History 

 Museum, are now rapidly becoming so perfect that one 

 may reasonably hope that he will, in common with all 

 ornithologists, be able to work in that institution with the 

 same comfort as in his own museum in Scotland. If in 

 future years the student of birds finds that at South 

 Kensington the work he loves can be done more ex- 

 peditiously and with command of a larger series of 

 specimens than in any other Museum in the world, his 

 gratitude will be largely due to the four naturalists we 

 have mentioned— Mr. Allan Hume, Messrs. O. Salvin and 

 F. D. Godman, and Capt. Wardlaw Ramsay— for the 

 unexampled generosity which has led them to present to 

 the British nation the wonderful collections which will 

 make our Ornithological Museum famous for all time. 



Many naturalists who read this article will remember 

 how, twelve years ago, the entire collection of bird- skins 

 in the British Museum was contained in a few book-cases 

 in a dingy cellar at Bloomsbury, where all the skins were 

 kept in wooden boxes — a barbarous method, which 

 was not only clumsy, but actually harmful to the 



specimens themselves. The development of the collec- 

 tion since that era is one which any English naturalist 

 may consider with pride. Not only is the invaluable 

 series of skins in the British Museum now well cared for 

 and properly housed, but the ratson d'etre of the large 

 collections in private hands has been removed. It is 

 admitted on all sides that had the facilities of study in 

 the old days been such as they now are in the Natural 

 History Museum, there would have been no need for 

 ornithologists to devote their private means to the 

 formation of the collections which have, however, now 

 become the foundation of the greatest Ornithological 

 Museum in the whole world. 



The three great collections which have enriched the 

 British Museum during the last two years have each 

 been, in their way, of supreme importance for zoological 

 science. The Hume collection was a perfect marvel in 

 the way of complete series of specimens. Not only are 

 the various plumages of the Indian birds exemplified in a 

 manner hitherto unheard of, but even the geographical 

 ranges of most of the species are illustrated in a perfect 

 way by the series of specimens contained in the col- 

 lection. The Salvin-Godman donation consisted of 

 American birds, and added hundreds of species to the 

 British Museum which were desiderata to that collection. 

 Though not so rich in series of various plumages as the 

 Hume collection, the number of gaps in the quota of 

 American birds which their donation filled was simply 

 enormous, and from being one of the most backward in 

 regard to its neotropical collection of birds, the British 

 Museum is now one of the foremost as regards the value 

 of its American series. 



The Tweeddale collection " takes up the running," so 

 to speak, where Mr. Hume left off, and it must not be 

 supposed that the donation now made by Capt. Wardlaw 

 Ramsay is merely the collection of skins left to him by 

 his uncle. To imagine this would be but a poor appre- 

 ciation of the energy which has led him during the last 

 i&wi years to develop and greatly increase the collection 

 by the addition of a large number of birds obtained 

 during his mihtary career in the East, and by hundreds 

 of other valuable specimens acquired since his uncle's 

 death. Thus the skins from the Kurrum Valley in 

 Afghanistan, and from the Karen Hills in Burmah, 

 obtained by Capt. Ramsay himself, are supplementary 

 additions of the highest value to the Hume collection, 

 inasmuch as Mr. Hume never had correspondents in these 

 parts, and the specimens from the Andamans and 

 Nicobars are also of great importance ; but of course the 

 interest of the Tweeddale collection centres round the 

 expedition to the Philippine Archipelago made by Mr. 

 Alfred Everett for the late Marquess. Mr. Everett visited 

 several islands on which no zoologist had previously trod, 

 and as a natural result he discovered some beautiful new 

 species of birds which are still unrepresented in any other 

 collection but that of Capt. Ramsay. Altogether Mr. 

 Everett furnished material for twelve important memoirs 

 by the Marquess of Tweeddale, and the number of Philip- 

 pine types now presented to the British Museum adds 

 immensely to the wealth of the donation. Lord Tweed- 

 dale was also greatly interested in an obscure family of 

 birds — the Drongos, or Crow-shrikes {Dicruridce) — and 

 possessed a wonderful collection of these birds, although 

 it may be stated that there is scarcely a family of Oriental 

 birds which is not strongly and completely represented in 

 the collection. 



Ornithologists will understand the nature of this noble 

 gift of Capt. Ramsay when they learn that in addition to the 

 collection of birds he has also presented the whole of the 

 splendid Tweeddale library (nearly 3000 volumes) to the 

 British Museum, to be placed in the Bird-Room, along- 

 side of the collection of skins, for the benefit of students 

 of ornithology. The Tweeddale library is one of the best 

 in the world, containing many rare volumes which 



