July 17, 1913] 



NATURE 



515 



corona he and his party secured during their expedi- 

 tion to Souk-Abras, in Algeria, in August, 1905. 

 Perfect weather was experienced on this occasion, and 

 the programme was carried out in its entirety. When 

 it i^ stated that the diameter of the moon on these 

 plates measures 7-5 inches, the scale of the reproduc- 

 tions can be better understood. The main object of 

 the expedition was to obtain the structure of the inner 

 corona by means of photography, and for this purpose 

 a horizontal telescope of 20 metres focal length was 

 used, fed by a ceelostat. The objective itself was by 

 Zeiss, .ind of 160 mm. aperture, and achromatised for 

 wave-lengths 531-7 and 405-1 w, the resulting solar 

 image being 19 cm. in diameter. In the introduction 

 to these plates Prof. Schorr gives details as to the 

 kind of photographic plates used, and the details of 

 exposure. Great pains seem to have been taken to 

 make the reproductions as representative of the 

 original negatives as possible, and the result is re- 

 markably successful. Each plate is accompanied by 

 a celluloid sheet over it, on which the correct orienta- 

 tion and prominent features are marked. The last 

 plate is a reproduction of a drawing bv Dr. Graff of 

 the structure of the inner corona, in which are com- 

 bined the details shown in all the negatives. For- 

 tunately, on the occasion of that eclipse the corona 

 was fully of quite extraordinary detail, especially in 

 form, and this record is therefore of particular interest. 

 The atlas is a valuable outcome of a most successful 

 expedition. 



KELVIN MEMORIAL WINDOW. 

 "T* HE memorial window to Lord Kelvin, subscribed 

 *■ for by engineers in Great Britain, Canada, and 

 the United States, was dedicated at a special service in 

 Westminster Abbey on Tuesday. The window is in the 

 easl bay of the nave on the north side. The light from 

 it falls upon the graves of Kelvin and Isaac Newton, 

 and immediately beneath it are the graves of Darwin 

 and Herschel. The window, which was designed by 

 Mr. J. N. Comper, is chiefly ecclesiastical and his- 

 torical in character. The lights contain two large 

 figures under canopies; and in front of the pedestals 

 nt these two figures are tablets held by angels, con- 

 taining the words : — "(1) In memory of Baron Kelvin 

 of Largs, (2) engineer, natural philosopher, b. 18.24, 

 d. 1907." Beneath these again are the arms of Lord 

 Kelvin and of Glasgow L T niversitv. 



The Dean of Westminster, in the course of an 

 address, is reported by The Times to have said that 

 fortv years ago there were at Cambridge an extra- 

 ordinary constellation of great men of mathematical 

 genius — Adams, Clerk-Maxwell, Cavlev, and Stokes — 

 occupying professorial chairs. Of the four, two had 

 been justly commemorated in the north aisle of the 

 Abbey. Another Cambridge man, William Thomson, 

 was destined to surpass his four friends. In 

 originality, in range of study, in ingenuity and re- 

 source, Kelvin was pre-eminent. It was said by 

 Goethe that to make an effort in the world two con- 

 ditions were essential — a good head and a good in- 

 heritance. Lord Kelvin and his four friends had both. 

 The new world of electricity had been already dis- 

 covered. They entered into that inheritance and 

 transformed its glories for the practical utility of 

 mankind. It was Kelvin who subdued the whole 

 province of the new realm of science. All through his 

 life, in the face of a strong prevailing current of 

 materialism, Kelvin preserved the simplicity of his early 

 ( hristian faith. He wrote in 1892 : " The real pheno- 

 menon of life infinitely transcends human science." 

 He spoke with the humility of a great man, and 

 many could look back with gratitude to the example 



NO. 228l, VOL. Ql] 



which the religious belief of a man of his gigantic 



intellect furnished in those of a younger generation. 



His name was one of the most epoch-making in the 



domain ot natural philosophy. 



i he chairman ot the Memorial Committee then 

 offered the window to the Abbgy, and it was gratefully 

 accepted by the Dean on behalf of himself and the 

 Chapter. 



THE EXETER MEETJNG OF THE ROYAL 



SA NIT A R \ ' INS TITUTE 

 AT the twenty-eighth congress of the Royal Sani- 

 x * tary Institute, held at Exeter on July 7-12, 

 many useful papers were contributed, one or two of 

 which dealt with research work of scientific interest. 



Mr. James Crabtree contributed a paper which 

 embodied some experiments on the lines of those 

 carried out by Dr. E. J. Russell and his co-workers 

 on the part played by protozoa in soils, the experi- 

 ments here recorded relating to sewage disposal beds. 

 From these experiments it is evident that the fauna 

 of the bacteria bed play an important part in keeping 

 the bed open and porous ; it seems probable that they 

 play a further part by the actual digestion of some 

 of the more easily resolvable colloidal matter pre- 

 cipitated on the beds. The conclusion arrived at 

 is that the animal population of the bacteria (contact) 

 bed is entirely advantageous in maintaining the 

 capacity of the bed, probably in keeping down ex- 

 traneous bacteria, and thus assisting purification to 

 some extent, and also by bringing about some actual 

 digestion of colloidal deposited matter. 



Dr. Gilbert G. Fowler and Mr. E. Moore Mumford 

 contributed an interesting paper on the bacterial 

 clarification of sewage. The area and cost of sewage 

 filter beds depends mainly upon the amount of colloidal 

 matter present in the sewage, and some confusion of 

 ideas is probably due to the fact that the ordinary 

 sewage filter is called upon to do two entirely different 

 things at the same time, namely on one hand to 

 oxidise, granulate, and finally discharge as humus 

 the colloidal matters present, and, on the other, 

 to oxidise and nitrify substances in true solution. 

 If this oxidising and coagulating process could be 

 brought about by suitable open-tank treatment before 

 the filtration process, it is obvious that the latter 

 could be enormously accelerated, if not dispensed with 

 altogether ; and the whole operation of sewage treat- 

 ment could be conducted on a much smaller area. 



In the course of a research on another matter, one 

 of the authors had occasion to study the reactions 

 of an organism occurring in nature in pit-water 

 impregnated with iron. This organism is a true 

 facultative organism, preferably an aerobe, and it 

 exercises a specific action on iron solutions. The 

 action of the bacillus on iron solutions proceeds in 

 two stages, in which the aerobic and anaerobic 

 actions appear to be symbiotic, at any rate under 

 the conditions occurring in nature. The aerobic 

 action is to precipitate ferric hydroxide from 

 iron solutions; while the anaerobic action is 

 to transform the hydroxide thus precipitated 

 into bog ore, with partial reduction of the iron to 

 a ferrous state. It was found that in order to pre- 

 cipitate the iron sufficiently the organism required a 

 certain proportion of albuminoid organic matter. It 

 was, therefore, natural to expert that ordinary 

 sewage matter could be utilised in this way. Experi- 

 ment, in fact, showed that a previously sedimented 

 sewage effluent could be effectively clarified in this 

 way when acted upon by this organism in presence 

 of small quantities of ferric salts, aerobic conditions 

 being maintained in the liquid bv means of a current 



