NATURE 



\_Nov. 30, 1 871 



A\'e then have A' = - 



f ' 

 and for the brilliance of the bright line spectnim, we get 



A' 



(6) 



If we neglect S, the loss of light in transmission through the 

 apparatus, and suppose/ = /', this becomes 



A' ^ 



mp 



(7) 



These fonnula; show that with a spectrnm of this kind we may, 

 without diminishing the brightness of the lines, increase the 

 dispersive power of our instrument to any extent by increasing 

 .its linear dimensions; if we increase the dispersive power hy 

 adding to the prism train, the case is different, since i' is a func- 

 tion of ;;, the number of prisms. 



AW' foiitt of Spectroscope. — I close the article with the sugges- 

 tion of a new form for a chemical spectroscope, which seems to 

 present some advantages in the saving of material and labour as 

 well as of light. 



The figure ( Fig. 4) sufficiently illustrates it, except that it may be 

 necessary to add that I have not represented any of the many pos- 

 sible convenient arrangements for reading off the positions of 

 lines obsen'ed. The centre of motion for the telescope is at c, 

 the collimator remaining fixed. 



The half prisms of heavy flint-glass are concave at the rear 

 surface, and diiedly cemented to the single crown glass lenses, 

 which form the object-glasses of telescope and collimator. There 

 is thus a saving of two surfaces over the common form ; and, what 

 is more impnrt.int, the prisms to fit telescopes of a given aperture 

 are considerably smaller on the face, and can be made from plates 

 of glass of less than half the thickness required by the ordinary 

 construction, a circumstance which greatly reduces the difficulty 

 of obtaining suitable material. 



NOTES 



We learn by British-Indian cable th-it the English Govern- 

 ment Eclipse Expedition arrived at Galle on Monday last ; all 

 well. The authorities in India and in Ceylon are doing every- 

 thing they can to assist the party. M. Janssen has gone to the 

 Neilghcrries. Mr. Lockyer is in communication with Colonel 

 Tennant. The weather was at that time fine. 



Proffssor John Young has written to the North British 

 Daily Mail, detailing the reasons for the notice of motion which 

 he gave in April last to the General Council of the University of 

 Glasgow, relative to the division of the chair of Natural History 

 in that University. The duties of the chair would render it 

 ncumbent on its occupant to teach, if required to do so, Zoology, 

 Comparative Anatomy and Physiology, Geology and Palaeonto- 

 logy, Mineralogy, Mining, Metallurgy, and possibly Meteorology. 

 Actually, Professor Young gives instruct on in Comparative 

 Anatomy and Geology. He is naturally extremely anxious that 

 he should no longer be called upon to teach subjects which, in 

 the present state of science, it is impossible can be efficiently 

 combined. It is to be hoped that, before long, the University 

 will see the necessity of instituting a separate chair of Geology, 

 as has recently been done at Edinburgh ; but where will be 

 found a Sir Roderick Murchison to endow it in so m\niificent a 



At the second M. B. Examination for Honours at the University 

 of London, Mr. William Henry Allchin, of University College, 

 has taken the Scholarship and gold medal, and Mr. Henry 

 Edward Southee, of Guy's Hospital, the gold medal in Medi- 

 cine ; Mr. Richard Clement Lucas, of Guy's Hospital, the gold 

 medal in Obstetric Medicine, and Mr. Ernest Alfred Elkington, 

 of ihe General Hospital, Birmingham, the gold medal in Forensic 

 Medicine. At the second B. A. and second B.Sc. Examination, 

 Mr. Thomas Olver Plarding, of Trinity College, Cambridge, 

 cbtained the Scholarship in Mathematics and Natural Philo- 



sophy. No gold medals were awarded in Animal Physiology, 

 Chemistry, Geology and Palceontology, or Zoology. 



Mr. Lazarus Fletcher, of the Manchester Grammar 

 School, was on Saturday last elected to the vacant scholarship at 

 Balliol College, on the foundation of Miss H. Brakenbury, for the 

 encouragement of the study of Natural Science. Mr. Hains- 

 worth, of the same school, and Mr. Greswell, of Louth School, 

 were also mentioned by the examiners as worthy of commenda- 

 tion. The scholarship is worth 70/. a year, and is tenable for 

 three years. 



With reference to the destruction of the Museum at Chicago, 

 we learn that Dr. Stimpson's own collection of North American 

 shells formed part of the Smithsonian Museum ; and that the 

 collection made by Professor Agassiz and Count Pourtales, in 

 their deep-sea explorations of the Gulf of Mexico, belonged to 

 the Cambridge Museum. Many of Dr. Stimpson's MSS. and 

 drawings have been published. Mr. Gwyn Jeffreys was, as oar 

 readers are aware, fortunately the means of saving some of the 

 shvdls from the Gulf of Mexico, which he is now engaged in 

 working out before returning. Many valuable specimens which 

 Mr. Jeffreys took to Chicago of course shared the fate of the 

 remainder ; some ol them, however, he hopes to be able to 

 replace. Professor Agassiz has offered Dr. Stimpson a place at 

 Cambridge, Mass., and to give him the means of again carrying 

 on dredging operations in the Gulf of Mexico. 



A FlNic young pair of the Grey seal (HaKcha'rus gryptis') has 

 just been added to the Zoological Society's living collection. 

 This species, although not uncommon on some pans of the 

 British coast, has never previously been received alive by the 

 Society. The present specimens were obtained near St. David's 

 in South Wales, where this seal is said to be of not uufrequent 

 occurrence. Besides this seal, the Society's collection also con- 

 tains examples of three other Phocidce — namely, the sea-lion 

 {Otaria jitbata), the Cape eared seal [Otaria piisilla), and the 

 common seal (Phoca vitiilina). 



In the Northern United States the richest marine fauna is to 

 be found in the vicinity of Eastport, Maine, the adjacent region 

 of the Bay of Fundy having become classic ground through the 

 labours of Stimpson, "Verrill, Packard, Morse, Webster, Hyatt, 

 &c. It is rumoured, according to HarpcPs ]Vcckly, that Mr. J. 

 E. Gavit, of New York, president of the American Bank-note 

 Company, and at the same time an eminent microscopist, has it 

 in contemplation with some friends to erect a building at East- 

 port, to be suitably endowed and maintained for the use of any 

 naturalists who may wish to avail themselves of the facilities it 

 may afford. We can only hope that so excellent an idea may be 

 realised at an early day. 



The latest advices from Captain Hall's expedition were dated 

 at Upernavik, September 5, being somewhat later than the in- 

 formation brought back by the Congress. After parting with 

 the Congress at Disco, Captain Hall sailed nearly north until he 

 reached the harbour of Proven, where he landed and endeavoured 

 to obtain dogs. In this, however, he was not very successful, 

 procuring only eighteen, most of which were not well fitted for 

 service. From Proven the Polaris proceeded to Upernavik, 

 arriving there on the 30th of August. He left that port on the 

 5 th of September, and continued on his polar journey. 



Among the movements of naturalists abroad, we understand 

 that Mr. J. Matthew Jones, F.L.S., President of the Nova 

 Scotian Institute of Natural Science, intends spending the 

 winter months in the Bermudas, for the purpose of more 

 thoroughly investigating the marine zoology of the group. 



Messrs. Wsstermann, of Brunswick, announce for early 



