592 



NATURE 



\Oct. 17, 1889 



in 1 621, but was re-detected, in its pristine brightness, by 

 Domenico Cassini at Bologna in 1655. The news seems 

 to have taken no less than three years to filter to the 

 Low Countries. Golius, of Leyden, was one of the first 

 to get hold of it, and he transmitted it to Boulliau, of 

 Paris, who thereupon perceived, plainly enough, a brilliant 

 star shining in the place of a usually telescopic one. As 

 an example of mental inertia comparable to that afiforded 

 by Hevelius with regard to the Orion nebula, it is worth 

 noting that the object had caught his eye twelve days 

 previously, but without rousing his attention. He im- 

 parted to Huygens his conviction that the Milky Way 

 "provided the material for such generations," among 

 which he included comets ; and judiciously wound up 

 his speculations by urging the necessity for continued 

 observation. 



His correspondent had anticipated the recommendation. 

 His interest in the '• renaissante of the Swan" (as he 

 termed it) is shown by various remarks ; but a more 

 formal essay on the subject, alluded to in a letter to the 

 Sicilian astronomer Hodierna, has not been preserved. 

 Huygens considered the star, on November 20, 1659, to 

 have lost none of its lately-acquired brilliancy. Boulliau, 

 however, had already noticed a diminution in size, though 

 not in lustre (a distinction to which he evidently attached 

 some importance), and on December 12 saw further 

 symptoms of fading in its pale and languid aspect. From 

 the decline which then set in, it has never completely 

 recovered, but has remained, since the abortive maximum 

 of 1665, undistinguished by conspicuous vicissitudes. 

 " P Cygni," as Janson's star is called in modern nomen- 

 clature, now betrays peculiarity of constitution only by 

 the bright hydrogen lines photographically discovered by 

 Prof. Pickering in its spectrum. 



Huygens's invention of the pendulum clock is a pro- 

 minent topic in the correspondence before us. He was 

 not without hope of solving, by its means, the ever- 

 recurring problem of longitudes, " if only it would bear 

 transport by sea"— a prudent qualification. Of curves 

 and quadratures, telescopes and lenses, chronometry, 

 meteorology, mechanics, the theory of numbers, much is 

 said, showing the working of thought along these various 

 lines of research. There is scarcely, in fact, a branch of 

 scientific history which is not usefully illustrated by these 

 valuable letters. A. M. Clerke. 



THE ANATOMY OF THE HUMPBACK WHALE. 

 The Anatomy of the Humpback Whale {Megaptera 



longimana). By John Struthers, M.D. (Edinburgh: 



1889.) 



'"pHERE is probably no order of Mammals which 

 -L during the last twenty-five years has been more 

 worked at than the Cetacea. The result has been that 

 we now possess a valuable body of information on both 

 the classification and anatomy of this most interesting 

 group of animals. On the continent of Europe, the 

 names of Eschricht, Reinhardt, Lilljeborg, Van Beneden, 

 and Gervais stand out most prominently as authorities ; 

 whilst in this country Sir Richard Ower, Profs. Flower, 

 Struthers, and Turner, Dr. Murie, and Prof. Macalister, 

 have all written valuable memoirs which have added 



largely to our knowledge of the whales. Through the 

 combined labours of these anatomists the order has been 

 rescued from the state of confusion into which it had 

 been thrown by some systematic writers, who, by regard- 

 ing almost every specimen stranded on our coasts as a 

 new species, had introduced a complexity of nomenclature 

 which was most puzzling. 



The humpbacked whale, the anatomy of which forms 

 the subject of Prof. Struthers's memoir, is, from its form 

 and structure, one of the most interesting of the occa- 

 sional visitors to our coasts. The number of specimens 

 the capture of which has been recorded in British waters, 

 prior to that of the specimen dissected by Dr. Struthers, 

 was only three : viz. a female cast ashore near Newcastle 

 in September 1829, and described by the late Dr. George 

 Johnston ; another female taken in 1863 in the estuary 

 of the Dee, the skeleton of which is in the Derby 

 Museum, Liverpool ; and an adult towed into Wick Bay 

 in March 1871, the skeleton of which was not preserved. 

 This whale is, however, not uncommon in the North 

 Atlantic, more especially off the coasts of Norway and 

 Finmark, and in the seas of Iceland and Spitzbergen, 



The specimen described in Prof. Struthers's memoir 

 was seen in the Firth of Tay, in the month of December 



1883. It was harpooned, but broke away from its 

 captors, was ultimately found floating dead off Bervie, 

 and was towed into Stonehaven Harbour on January 8, 



1884. It is fortunate that it fell into the hands of so 

 competent an anatomist and so enthusiastic a cetologist 

 as the Aberdeen Professor. Thanks to his untiring 

 energy and industry, he has furnished us with a monograph 

 on the external characters, the skeletal anatomy, the- 

 muscular anatomy of the pectoral limbs, and the con- 

 nections of the pelvic bones and rudimentary hind limbs- 

 of this animal, far more precise and detailed than had 

 been given by any previous anatomist. He has added 

 also greatly to the value of his description by instituting 

 a comparison between the skeleton of Megaptera and 

 that of Balcenoptera musculits. The memoir will have to 

 be studied by all cetologists who wish to have an exact 

 knowledge of the anatomy of this great baleen whale. 



OUR BOOK SHELF. 



First Mathematical Course. Blackie's " Science Text- 

 Books." (London: Blackie and Son, 1889.) 



This little work, comprising arithmetic, algebra (as far 

 as simple equations), and the first book of Euclid, is 

 adapted to the requirements of the examinations of the 

 Science and Art Department in mathematics (Subject V.), 

 first stage. The more elementary parts of arithmetic 

 have been briefly treated, as the pupil will have most 

 probably reached fractions, but great attention has been 

 paid to the examples, which are both numerous and 

 judiciously chosen. The algebraical part is completed 

 up to and includes simultaneous equations, and here, as 

 in the arithmetical part, we have a great number of well- 

 arranged examples, including those set for this stage in- 

 previous examinations. Part III. consists of the first 

 book of Euclid with exercises on the various propositions. 

 Preceding the answers to the examples is an appendix 

 containing specimen examination papers set by the above- 

 named Department. Teachers, who require a great number 

 of easy examples on these three branches of mathematics,, 

 will find this book very useful 



