June ;^o, 1910] 



NATURE 



529 



ion, and starts from the principle that "the pheno- 

 menon must manifest itself in this, that, ceteris 

 paribus, the more distant stars will be redder than 

 the nearer ones." As a measure of redness he em- 

 ploys the difference, photographic minus visual 

 magnitude, derived from the Draper catalogue and 

 the Harvard revision. It would be profitless to use 

 direct determinations of parallax, for the material at 

 hand is far too scanty and untrustworth}-. Hence he 

 derives the measures of distance from his own statis- 

 tical discussions, which have enabled him to express 

 the average parallax of a star as a function of its 

 magnitude and proper motion. The necessan,- data 

 have thus been found for 1433 stars, and separate 

 equations have been formed for the different spectral 

 classes and certain ranges of proper motion within 

 each class. It is impossible here to follow the rather 

 complicated discussion in detail, but the result 

 obtained on certain simple assumptions as to the 

 nature of the scattering of light implies a loss of 



000867 of total Iight = cco945 of mag. for photographic rays 

 000427 „ =000465 „ visual rays 



in the case of a star the parallax of which is o"!*, or the 

 distance of which is 326 light-years. Kapteyn con- 

 siders that these numbers represent lower limits, and 

 finds no difference between galactic and extra-galactic 

 regions of the sky so far as selective absorption is con- 

 cerned. 



Despite the contradictor}- nature of the evidence, 

 it must be felt that the whole subject is full of interest. 

 It is now receiving the most critical and exhaustive 

 discussion, and the need for fresh material will stimu- 

 late original and appropriate observations. It is 

 pleasant to learn from Prof. Kapteyn that the 

 plan of work for the 60-inch reflector on Mount 

 Wilson includes special provision for this line of study. 

 Efforts directed with a serious purpose and pursued 

 with sincerity do not go unrewarded, though the 

 shape of the reward may not always be according to 

 expectation. H. C. P. 



NOTES. 



The list of Birthday Honours was published on Friday 

 last, but, as usual, men of science do not figure largely in 

 it. Among the new Privy Councillors we notice the name 

 of Sir William Mather, who has done much to promote 

 technical education. The honour of Knighthood has been 

 conferred upon Mr. H. Hall, His Majesty's Inspector of 

 Mines for the Liverpool and North Wales district, and 

 Dr. A. Hopkinson, Vice-Chancellor and principal of the 

 Victoria Universitv' of Manchester. Colonel F. B. Longe, 

 Surveyor-General of India, and Dr. R. T. Glazebrook, 

 F.R.S., become Companions of the Bath (C.B.). Mr. 

 J. H. Marshall, director-general of archaeology in India, 

 Mr. C. Michie Smith, director of the Kodaikanal and 

 Madras Observatories, and Dr. M. Aurel Stein, super- 

 intendent of the ArchaK)logical Survey, Eastern Circle, are 

 appointed Commanders of the Indian Empire (C.I.E.>. 

 The order of C.M.G. has been conferred upon Dr. A. D. P. 

 Hodges, principal medical officer of the Uganda Pro- 

 tectorate, in recognition of his services in the suppression 

 of sleeping sickness, and Prof. T. W. Edgeworth David, 

 F.R.S., of the University of Sydney. Mr. C. O. Water- 

 house, of the British Museum (Natural History), has been 

 appointed a Companion of the Imperial Service Order. 



Sir Wiluaji Ramsay, K.C.B., F.R.S., has been elected 

 an " Associ^ Etranger " of the Paris Academy of Sciences, 

 in the place of the late Prof. Alexander Agassiz. 



The .\lbert medal of the Royal Society of Arts for the 

 current year has been awarded by the council to Madame 



NO. 2122, VOL. 83] 



Curie, for the discovery of radium. The discovery, which 

 was the outcome of Prof. Becquerel's researches into the 

 radio-activity of uranium and its compounds, was made 

 jointly by Madame Curie and her husband, Prof. Curie, 

 professor of physics at the Sorbonne, in 1898. Prof. Curie 

 died in April, 1906, and in May of the same year the 

 faculty of sciences paid his widow the distinguished honour 

 of appointing her his successor. She has since con- 

 tinued, on her own account, the researches she commenced 

 in association with her husband. The Davy medal of the 

 Royal Society was awarded to Prof, and Madame Curie in 

 1903, and the importance of the discovery has been fully 

 recognised by the scientific world. 



The King has consented to become Patron of the Royal 

 Societv- of Arts in succession to King Edward the Seventh, 

 who became Patron on his accession, after having filled the 

 office of president of the society for thirt)--eight years. 



The President of the Board of Trade has appointed a 

 committee to inquire what degree of colour-blindness or 

 defective form-vision in persons holding responsible posi- 

 tions at sea causes them to be incompetent to discharge 

 their duties ; and to advise whether any, and, if so, what, 

 alterations are desirable in the Board of Trade sight tests 

 at present in force for persons serving or intending to 

 serve in the merchant service or in fishing vessels, or in 

 the way in which those tests are applied. The committee 

 consists of the Right Hon. A. H. D. Acland (chairman), 

 Lord Rayleigh, O.M., F.R.S., Sir Arthur Rucker, F.R.S.. 

 Mr. Raymond Beck, Captain T. Golding, Prof. F. Gotch, 

 F.R.S., Mr. N. Hill, Mr. E. Nettleship, Mr. J. H. Parsons, 

 Prof. J. H. Poynting, F.R.S., and Prof. E. H. Starling, 

 F.R.S. Dr. W. Watson, F.R.S., and Mr. S. G. Tallents 

 will be secretaries to the committee. 



With reference to Mr. Winston Churchill's statement in 

 the House of Commons on June 16, " that the time has 

 now arrived when a definite eflfort should be made to break 

 new ground and set up a higher standard " of safety in 

 mines, we learn that a committee, appointed by the council 

 of the Royal Society of Arts, and under the chairmanship 

 of Sir Henry Cunynghame, K.C.B., is now considering the 

 relative merits of a number of life-saving appliances which 

 have been submitted in response to an offer, under the 

 Fothergill Trust, of a gold medal or prize of 20/. for the 

 best portable apparatus for enabling men to undertake 

 rescue work in mines or other places w-here the air is 

 noxious. The committee of the society is in communica- 

 tion with the South Midland Coal Owners Mine Rescue 

 Experimental Committee, which is also conducting 

 exhaustive inquiries w^ith the view of discovering the most 

 suitable apparatus for use in the South Midland coal- 

 fields. 



The King held his second Accession Court for the recep- 

 tion of addresses at St. James's Palace on June 22. Among 

 the addresses presented were eight from universities and 

 a number from learned societies. The King made special 

 replies to the Universities of Oxford, Cambridge, Edin- 

 burgh, Dublin, and London. To the representatives of 

 Oxford University his Majesty remarked: — ''It is my 

 desire to follow the example of my father and of Queen 

 Victoria in sustaining and in fortifying those seats of learn- 

 ing on whose prosperity and influence the character 

 and repute of our civilisation largely depend. Among 

 them the University of Oxford, with its world-famous 

 traditions of steadfastness and loyalty, will ever hold an 

 honoured place." The reply to Cambridge University 

 included the words : — " Your famous Universitv mav count 



