782 



NATURE 



'August 19, 1920 



instruction and the advancement of science. The 

 reports of this Commission are most valuable 

 records of the position and needs of science, and 

 if the recommendations had been put into force 

 this country could easily have been in advance of 

 all others as regards scientific development. 

 When the work of the Commission was com- 

 pleted in 1875 Sir Norman was transferred to 

 the Science and Art Department. He afterwards 

 became professor of astronomical physics in the 

 Royal CoUeg-e of Science, and was director of 

 the Solar Physics Observatory at South Ken- 

 sington from 1885 to 1913. He was elected a 

 fellow of the Royal Society in 1869, was Rede 

 lecturer to the University of Cambridge in 1871, 

 and Bakerian lecturer to the Royal Society in 

 1874, in which year he received the Rumford 

 medal of the society. In 1875 the Paris Academy 

 of Sciences elected him a corresponding member 

 in the section of astronomy. He was a corre- 

 sponding member of numerous national scientific 

 societies, and honorary member of many others. 

 He received honorary degrees from the Universi- 

 ties of Oxford, Cambridge, Glasgow, Edinburgh, 

 and Aberdeen, and the Order of Knight Com- 

 mander of the Bath was conferred upon him by 

 the King in 1897. 



Sir Norman Lockyer's early spectroscopic work 

 was devoted to the sun. His first observations 

 were directed to a scrutiny of the spectrum of sun- 

 spots as compared with that of the general 

 surface. In the course of the paper in which 

 these observations were described, read before 

 the Royal Society on November 15, 1866, he 

 remarked: — "May not the spectroscope afford 

 us evidence of the existence of the ' red flames ' 

 which total eclipses have revealed to us in the 

 sun's atmosphere, although they escape all other 

 modes of examination at other times?" The 

 spectroscope he then employed proved to be of 

 insufficient dispersive power for his researches, 

 but by the aid of the Government Grant Com- 

 mittee of the Royal Society an instrument of 

 greater power, though not quite complete, was 

 obtained on October 16, 1868. Four days later 

 his efforts were crowned by the detection of a 

 solar prominence by means of the bright lines 

 exhibited in its spectrum. An account of this 

 discovery was immediately communicated to the 

 Royal Society and to the Paris Academy of 

 Sciences. Meanwhile had occurred the total solar 

 eclipse of August 18, and Dr. Janssen, who had 

 observed with eminent success the spectrum of 

 the prominences during the eclipse, came to the 

 conclusion that the same mode of observation 

 might enable one to detect them at any time, 

 and he saw them in this manner the next day. 

 The first account of the discovery, which was 

 sent by post, reached the Paris Academy a few 

 days after the communication of Sir Norman 

 Lockyer's observation of October 20, and, as was 

 described in Nature of May 20 last, a medal was 

 struck in honour of the joint discovery. 



This notable application of the spectroscope re- 

 vealed the prominences as local disturbances in 

 NO. 2651, VOL. 105] 



the continuous luminous layer which Sir Xorman 

 Lockyer called the chromosphere, and from the 

 field of research opened by his discovery rich 

 harvests have since been reaped. The gas, named 

 by him helium, commonly occurring in solar pro- 

 minences, was not isolated on the earth until 

 twenty-seven years later, when Sir William Ram- 

 say extracted it from the mineral cl^veite. Now, as 

 Prof. McLennan has described in these columns, it 

 is possible to obtain millions of cubic feet of helium 

 per day from natural gas in Alberta, and there 

 is every reason to believe that this supply will 

 become of immense scientific and industrial value. 

 It is beyond the bounds of this general record 

 of Sir Norman Lockyer's scientific services to 

 venture into the field of astronomical physics 

 which he made particularly his own. An apprecia- 

 tive account of that work will be contributed to 

 a later issue by a spectroscopist familiar with its 

 special significance and value. Here \Ve need 

 only remark that Sir Norman's meteoritic hypo- 

 thesis of celestial evolution is chiefly responsible 

 for the change of view which has taken place as 

 to the nature of nebulae and the existence of stars 

 of increasing as well as of decreasing tempera- 

 tures. Dark nebulae — sheets or streams of non- 

 luminous cosmic dust — are no longer considered 

 hypothetical, but are as real as dark stars, and 

 the incipient luminosity of nebulae in general 

 represents the visible portion only of vastly more 

 extensive congeries of invisible cosmic matter. 

 Some of the most noteworthy discoveries of 

 astronomical science in recent years are, indeed, 

 those which suggest or demonstrate that space 

 may include as much dark matter as bright, and 

 they largely owe their origin to Sir Xorman 

 Lockyer's meteoritic hypothesis and the classifica- 

 tion of stellar types based upon it. 



In his work and conclusions upon the subject 

 of dissociation, Sir Norman Lockyer was like- 

 wise much in advance of his times. Fifty years 

 ago he was convinced by his spectroscopic 

 observations that the view that each chemical 

 element had only one line spectrum was errone- 

 ous, and that the various terrestrial and solar 

 phenomena were produced by a series of sim- 

 plifications brought about by each higher tem- 

 perature employed. In his studies of dissocia- 

 tion he was really collecting facts concerning the 

 evolution of the chemical elements, and he 

 pointed out especially that the first steps in this 

 evolution were probably best determined by 

 observations of stellar spectra. 



Sir Norman Lockyer was the chief of eight 

 British Government solar eclipse expeditions, 

 and organised the programmes of several others 

 while director of the Solar Physics Observatory. 

 His use of the slitless spectroscope during the 

 eclipses from 1871 onwards provided a wealth of 

 information for study. From the photographs 

 obtained during the total solar eclipse of 1893 

 the wave-lengths of many chromospheric and 

 coronal lines were determined, and a very com- 

 plete series of pictures and spectra of the corona 

 and chromosphere was obtained during the 



