July 5) 1883] 



NA TURE 



231 



them right and left, the rays being composed of sharp 

 radial lines, separated by furrows of markedly less 

 brilliancy." 



After there had been time to examine the photographic 

 records of the eclipse in connection with the above descrip- 

 tion, the enormous difference between the photograph 

 and the eye picture was fully recognised, and in my 

 lecture at the Royal Institution on the eclipse, after 

 referring to the actinic corona, to the striking similarity in 

 the details of the photographs taken at different times 

 and in different places, I said : " The solar nature of most, 

 if not all, of the corona recorded on the plates is esta- 

 blished by the fact that the plates, taken in different 

 places, and both at the beginning and end of totality, 

 closely resemble each other, and much of the exterior de- 

 tailed structure is a continuation of that observed in the 

 inner portion independently determined by the spectro- 

 scope to belong to the sun." 



Passing from the photographs to the drawings, I 

 pointed out that in Mr. Holiday's sketch, for instance, we 

 got an infinite number of dark radial lines extending 

 down to the moon, with a greater extension than in the 

 photographs, though in some places the shape of the 

 actinic corona and some of its details were shown. 



Thinking that this difference might be explained by 

 different lights being superposed, so that of two super- 

 posed lights the naked eye used one, and the photo- 

 graphic plate the other, 1 asked the question whether 

 the facts might not be reconciled, and really harmonised 

 with what was actually seen in the telescope, even by 

 supposing that the visual image, this glare let us call it, 

 was sifted in the telescope by using greater or less magni- 

 fication in the same way as it was separated out on the 

 photographic plates and in our eyes by the different 

 qualities of the light producing the visual and photo- 

 graphic images. 



From this point of view, therefore, I regard Mr. 

 Hasting's observation as one of very great interest, and I 

 believe that it throws light upon a good many prior obser- 

 vations. I do not think, however, that any one will go 

 with him when he proposes to abolish a true corona at the 

 sun, for the reason that the observations to which I have 

 drawn attention show that it is really a dual phenomenon 

 as I pointed out in 1870, and although diffraction at the 

 moon's edge may be the cause of one part, it cannot be 

 the cause of the other. It is, perhaps, almost too early 

 yet to speculate upon the changes in our views of the 

 chemical nature of the external boundary of the sun's 

 atmosphere which may be brought about by a complete 

 discussion of the question which these observations again 

 bring to the front. I long ago pointed out that the fact 

 of getting in the spectroscope an indication of a line at so 

 many minutes of arc from the limb of the dark moon, 

 was by no means a proof of the existence of a vapour or 

 gas at that height above the sun. Maclenr's observation in 

 1870 was of course the test, for the reason that if such a 

 caveat were not available we must assume the existence of 

 coronal matter between us and the dark moon. But in any 

 case it is not too early to bear ihis in mind, that if in our 

 spectroscopes we have been dealing w ith a true glare, 

 from whatever cause produced, there will be an almost 

 complete inversion necessitated, and in this way : the 

 brilliancy of any particular wave-length of the glare 

 may either depend upon the area of the surface 

 at the sun producing light of that wave-length, or 

 upon its inherent intensity. Now if we assume that 

 only the inherent intensity is to be considered, then 

 obviously the region of greatest temperature will 

 cause the brightest light. The brightest light will 

 therefore be produced in the lowest level of the solar 

 atmosphere, but because of the glare it will appear 

 to extend to the greatest distance from the sun. It may 

 therefore have been that the line 1474, instead of indi- 

 cating, as it has been supposed to do, that a substance 



which gives a line at the part of the solar atmosphere 

 most removed from the photosphere is really produced by 

 that part of the atmosphere, was produced at that part of 

 the atmosphere nearest the photosphere, and really at 

 first sight— although this is by no means a matter on which 

 one would wish to commit one's self hastily — it does seem 

 as if this view would harmonise a great many facts 

 which are very difficult of explanation in any other way. 



I discovered the line 1474 in the chromosphere on 

 June 6, 1869, and up to that time no bright line had been 

 observed beyond those belonging to the spectra of hydro- 

 gen, sodium, and magnesium, with the exception of one 

 line of barium, which was first seen in March, 1869. Now 

 we know from the long-extended series of such observa- 

 tions for which we have to thank the industry of the 

 Italian observers, that the line 1474 is now seen more per- 

 sistently than any line which is not recorded in the 

 spectra of hydrogen, magnesium, and sodium. The 

 eclipse of last year taught us, if it taught us anything, 

 that the lines which are thus persistent are the lines pro- 

 duced at the temperature of the hottest layers, and, if sub- 

 sequent inquiry strengthens the view that the height to 

 which the line 1474 appears to extend is really due to the 

 depth at which the substance which produces it is re- 

 stricted, the persistence of 1474 in ordinary chromo- 

 spheric observations will be at once explained. 



J. Norman Lockyer 



AGRICULTURE IN JAPAN 1 



DR. LIEBSCHER'S little work is the result, the author 

 tells us, of his investigations during an eight 

 months' sojourn in Japan in 1880. A cursory glance at 

 the contents shows that it bears the physiognomy of a 

 strictly scientific work. The work is divided into five 

 parts :— ( 1 ) The condition of the climate and its influence 

 upon the land-products ; (2) the condition of soils and its 

 influence upon the land-products ; (3) the social condition 

 before the year 1S6S (before the reformation) ; (4) the refor- 

 mation and reorganisation of the State since the year 

 1868; (5) foreign commerce. I shall notice shortly each 

 chapter with some remarks. Beginning with the first 

 chapter, Dr. Liebscher commences with the monsoon, 

 within whose sphere Japan is situated. It has, as is well 

 known, a certain determined direction during the wlv le 

 year. The summer (south-west) monsoon comes from 

 the south-we=t from April to September, while the 

 winter (north-east) monsoon comes from the nort' - 

 east during the rest of the year. To the first, ac- 

 cording to Dr. Liebscher, Japan owes its tropic il 

 flora, such as Chamarops excelsa, Tkea viridis, C 

 revoluta, &c, and to the same he attributes the 

 chief land-products, such as cotton, sugar-cane, tobacc, 

 Indian corn, and rice. Why the summer monsoon is 

 so favourable to the growth of the land-products is because, 

 says the author, it causes a warm temperature, and the 

 abundant precipitation of rain (maximum 1794 mm. in a 

 )ear). He ignores then altogether the geographical posi- 

 tion of Japan, that on one side she lies partly in a sub- 

 tropical and temperate zone, on the other she is sur- 

 rounded on all sides by a large body of water. The 

 north-east monsoon brings a dry and terribly cold winter, 

 though somewhat modified by the "Kuro-Siwo" current 

 and "this monsoon is the sole factor that renders the 

 climate unfavourable, causing the remarkable pheno- 

 menon of the "freezing of the soil." Dr. Liebscher says, 

 the regular courie of the monsoon assures the people 

 who happen to inhabit those lands which lie within the 

 sphere ot that wind, of a never-failing good crop of rice. 

 Thus we are accustomed to depend solely upon rice, and 



1 " Japan's landwirthschaftliche und allgemeinwirthschaftliche Verhaltnisse 

 nach eigenen Ueubachmnj-en dargestellt." Von Dr. G. Liebscher. (Jena 

 1882.) 



