January 29, 1897.] 



SCIENCE. 



175 



because I failed to find an adequate account 

 in such standard elementary text-books as 

 came to my hands. Thus the explanation 

 given in Daniell's physics is empiric and 

 about within the limits of Perry's little 

 book on tops. Ganot and Deschanel, Bar- 

 ker and Carhart, avoid the matter alto- 

 gether. Kelvin and Tait's ' elementary ' 

 treatise has a single paragraph, intelligible 

 at once, no doubt, to the authors. Peddie 

 puts a slight expansion of this paragraph 

 into his book. Even Violle's large new 

 work says nothing about tops. In the Ger- 

 man books, like Miiller-Pouillet, Wiillner 

 and the excellent treatise of Mousson, the 

 phenomena are interpreted by aid of a sug- 

 gestion of Poggendorfif's, the very object of 

 which is to dodge the principles of rotation 

 involved under cover of a reference (' nur 

 durch hohere Rechnung ') to Euler. Yet 

 gyrostats of diverse forms usually abound in 

 physical cabinets. Supposing an instructor 

 is not on the outlook for special entertain- 

 ment for his children, of what use is such 

 apparatus, I ask, if it be not to furnish the 

 most striking tests imaginable of the truth 

 of the above fundamental doctrines of rota- 

 tion. 



C. Baeus. 

 Bkown University, 



Providence, R. T. 



ZOOLOGICAL NOTES. 

 nansen's discovery of the breeding 

 grounds of the rosy gull. 

 Of the result of Hansen's Expedition thus 

 far announced one of the most interesting, 

 at least to ornithologists, is the reported 

 discovery of the breeding grounds of Ross' 

 Gull, also known as the Wedge-tailed or 

 Rosy Gull {Rhodostethia rosea). In a letter 

 published in the London Daily Chronicle last 

 November, Dr. Nansen stated that he found 

 flocks of Rosy Gulls on August 6th, in lati- 

 tude 81° 38', east longitude 63°. The birds 

 were seen near four small islands called 



' Hirtenland ' by Nansen, a little northeast 

 of Franz Josef Land. While Nansen did 

 not actually find nests, he found the birds 

 abundant, and concluded that their nests 

 were probably^near by. Every item of in- 

 formation regarding this rare bird is of 

 interest, and in the December number of 

 the OrnitJiologische Monatsberichte (pp. 193- 

 196), Dr. Herman Schalow calls attention 

 to the importance of Hansen's announce- 

 ment and takes occasion to review briefly 

 the history of the species. 



There seems to be no reason to question 

 the correctness of Nansen's determination 

 of the birds or his surmise that they were 

 breeding not far away. The wedge-shaped 

 tail and the rosy tinge of the plumage 

 (both noted by Nansen) are unmistakable 

 characters of the species, and the presence 

 of the gulls in such numbers in that high 

 latitude renders it very probable that they 

 were breeding. The Rosy Gull has long 

 remained one of the rarest gulls. It was 

 described from a specimen collected by Sir 

 James Clark Ross in 1823, on Melville Penin- 

 sula, but in the next half century only a 

 few individuals were taken and these in 

 widely separated localities. In the autumn of 

 1881 Murdoch observed large numbers at 

 Point Barrow, Alaska, apparently migra- 

 ting from the west to the northeast. Al- 

 though he secured a good series of speci- 

 mens, he could add little to the life history 

 of the species, and no other naturalist in 

 Alaska has had the good fortune to meet 

 with it in such numbers. This gull has 

 also been taken in North America at St. 

 Michael's, Alaska, and Disco Bay, Green- 

 land, but it was not seen by the Lady Frank- 

 lin Bay expedition. It was met with off the 

 Siberian coast by the Jeannette Expedition, 

 and was recorded by Payer between Nova 

 Zembla and Franz Josef Land, only a few 

 degrees to the south of the islands where 

 Nansen found it. 



The Rosy Gull is a typical arctic circum- 



