4i6 



NATURE 



[January 25, 19 u 



of Alpine rivers as inexhaustible stores of cnei^iy. 

 Had we the same in Britain wc could contemplate 

 with equanimity the exhaustion of our coalfields. 



CELESTIAL Sl'ECTROSCOl'Y.' 



THE publication referred to below contains .m 

 account of six separate and distinct investiga- 

 tions, which have been grouped together under the 

 above heading. In part i. are given the results of a 

 comparative study of the sun (Fraunlioferic), chromo- 

 sphere, and lower type star spectra in relation to the 

 sun-spot spectrum. Part ii. contains an account of 

 an investigation into the spectrum of « Ursse Majoris 

 as compared with the normal Sirian spectrum. Under 

 part iii. is found a discussion of the occurrence of 

 nitrogen lines in the stellar spectra, and under part iv. 

 lists of the enhanced lines of certain metals, which 

 have not previously been published. The wave-lengths 

 of certain well-defined lines of simple and definite 

 origin, which are peculiarly suitable for radial velocity 

 measurements, are given in part v., while under 

 part vi. are grouped the wave-lengtiis of those well- 

 marked lines occurring in celestial spectra for which 

 no terrestrial equivalents have yet been found. 



It may be said at once that the two last sections of 

 this book should prove of great value. It is mani- 

 festly impossible to obtain accurate results in any 

 radial velocity measurements unless the selected 

 spectrum lines are at once simple in structure and of 

 known origin. The publication of a list of such lines 

 occurring in the spectra of nine different types (Ken- 

 sington) must certainly aid those engaged in this par- 

 ticular branch of stellar spectroscopy. 



The first part of the book is devoted to a comparison 

 between the sun spectra and those of Capella and 

 .Vrcturus, considered especially in reference to the 

 spectrum of sun-spots. Certain of the Fraunhofer 

 lines are found to be considerably modified in intensity 

 in the .Arcturus spectrum, and it has been definitely 

 established by Hale and Adams that the same lines 

 are affected in sun-spots. A close comparison of the 

 Kensington measurements with those taken at Mount 

 Wilson is given as far as they overlap, and though 

 there are present in each certain lines not common 

 to both, the two sets of observations are strikingly 

 concordant. It has always been held by Sir Norman 

 Lockyer and his co-workers that the comparison be- 

 tween the spectra indicate that the temperature of 

 •Arcturus and that of the sun-spots are comparable 

 and lower than that of the rest of the solar reversing 

 layer. Although other theories have been advanced, 

 the latest observations go to show that the Kensington 

 theory is the right one. 



The second chapter deals entirely with the spectrum 

 of « Ursae Majoris, the lines of which have been 

 measured and as far as possible traced to their origin. 

 The differences between this spectrum and those of 

 Sirius and a Cygni arc given, and the general con- 

 clusion is drawn that « Ursae Majoris must be placed 

 between the Sirian and the Procyonian group on the 

 Kensington temperature scale. 



It is impossible in a short notice to enter into the 

 details of this work, so many branches of which have 

 been grouped together. Suffice it to say that the 

 whole investigation stands on the same high plane as 

 all those carried out in the Solar Physics Observator}', 

 and the author is to be congratulated on bringing a 

 laboriou? recearch to a successful conclusion. 



1 " Re^earche* nn the Chemical Origin of Various Lines in Solar and 

 •Stellar Spectra ; beinr the Results of Investigations made at the Sol.ir 

 Ph>-sirs Obser\-ator>', South Kensineton. after discussion." By F. E. 

 Baxnndan. Pd. vii4-77. (I.ondon : H.M. S>ationer>- Office, 1910.) 

 Price 4S. Sti. (Solsr P><>-sics Committee, under the Direction of Sir Norman 

 l.ockyer. K.CB., F.R.S.) 



NO. 2204, VOL. 88] 



* YELLOW JACK." 



AMF-ILANCHOLY interest attaches to this volume 

 inaiimuch as it was the last wr^k d. mi, ,1 l,\ its 

 gifted author Ijcfore his premature <: 

 to emph.'isise the loss to tropical i 

 thereby. 



The book is a complete treatise on yelln 

 the ■■ yellow jack" of the earlier na\ 

 dread disease which so often broke out 

 suddenness and severity on ship^- 

 west coast of Africa, the West li 

 .'Xmerica, and parts adjacent thereto. !■ 

 is somewhat peculiar in that it is pracii 

 to that part of the globe between th- 

 latitude 40° north and south, and of 1 



f 



Fig. j.—Stege" 



mosquito which carries y 

 Fever and its Prevention. 



east and 100° west. It is true that outbreaks of th 

 disease have occurred somewhat outside these limit^ 

 e.g. in North Italy, French seap>orts, Swansea, an 

 Southampton in this country (a few cases only». an 

 at times .severely in New York and Philadelp"'; 1. bi 

 in these districts it has never obtained a iVv .thol< 

 The reason for this geographical distribution is ass< 

 ciated partly with the endemic areas which natural) 

 exist in West Africa and Central America, and parti 

 by reason of the fact that the disease is transmitte 

 by a species of mosquito, the Stegomyia fasciai 

 (calopus), the distribution of which is practical! 

 world-wide between the parallels of latitude 40° nort 

 and south. Thus in Europe, the Stegomyia is four 

 in southern Spain, Italy, Malta, and Greece, and 



1 "Yellow Fever and its Prevention : a Manual f>r Mediral Stjie-iisa: 

 Practitioners." By Sir Robert W. Boyce, F.R.S. Pp. xv-f-3>o. ([■■sAx 

 John Murray, 1911.) Price 10*. 6rf. net.-- 



