146 



NA TURE 



\June 14, 1883. 



obtain a very small and intensely bright image of the 

 corona, while the use of the prism of 60°, giving as small 

 a dispersion as possible, still allowed a really useful 

 amount to be secured. This instrument succeeded well. 

 We do not know the number of photographs obtained by 

 it, but if the instructions were carried out to the letter, 

 seventeen should have been obtained. 



" We co ne next to the instrument by means of which 

 the photograph of the flash of bright lines to which we 

 have referred was obtained. This on the official list is 

 called the 'integrating Hilger.' It is a spectroscope 

 armed with a collimator of very great focal length and 

 directed merely to the sun's place, no image of the sun 

 or corona, therefore, falling on its slit as is usually the 

 case. The light from all the regions near the sun is 

 mingled together, a photograph of the spectrum of this 

 mixture being the special aim of the instrument. Messrs. 

 Lawrence and Woods are evidently satisfied with the 

 work in this direction, the code word they use indicating 

 that they consider the results to be good ones. The 

 moving plate with which the instrument is fitted was 

 exposed t«o minutes before, and withdrawn from ex- 

 posure two seconds after, totality. Knowing, therefore, 

 as we do, that one flash was photographed, we may 

 reasonably hope that this was the case also with the 

 other, and as the instructions were to allow the plate to 

 fall through one inch in eight minutes, we may also 

 expect to get a comparison between the flash before and 

 the flash after totality. 



"The slit spectroscope armed with two prisms, which 

 was provided by Captain Abney for the observations made 

 last year in Egypt, was utilised also on this occasion with 

 good results. Only one photograph was looked for from 

 this instrument, one which would be exposed from the 

 beginning until the end of totality. 



"The prismatic camera, the instrument on the model 

 of that used first in the eclipse of 1875, in which the 

 corona forms its own slit, for some reason or other, 

 does not appear to have been so successful in this 

 eclipse, although it was tolerably so in that of last year. 



" The attempt which has been least successful is that in 

 which Prof. Rowland's concave grating was used as a pris- 

 matic camera, similar to that to which we have just referred. 

 It was hoped to obtain a photograph of the blue end, both 

 in the first and in the second order spectrum, but the 

 results obtained are ciphered as bad. Seeing that Dr. 

 Janssen was successful in his attempt to obtain large- 

 scale photographs of the corona, we need not regret so 

 much that our attempt to photograph it on a scale of four 

 inches to the sun's diameter was unsuccessful. 



"The small photoheliograph that was employed to such 

 good purpose in Egypt last year has again given excellent 

 results, which will be of the highest importance, as they 

 will have been carefully executed, and the American 

 party have taken no photographs themselves on the 

 present occasion. 



" The English observers telegraph that the lines obtained 

 in the spectrum of the corona by these various methods 

 are chiefly those of hydrogen. This, of course, does not 

 apply to the flash we have spoken of. They add that the 

 prominences were almost absent. This is an extremely 

 important fact, because it shows what entire justification 

 there was for the prediction made for the present eclipse 

 after that of 187s, observed in the United States. That 

 eclipse occurred at a minimum sunspot period, and the 

 hydrogen lines were then seen only with difficulty, while 

 the continuous spectrum of the corona was more or less 

 brilliant. In the present eclipse the hydrogen lines were 

 well seen with a very brilliant corona, as was anticipated 

 would be the case at a period of sunspot maximum. 

 This, perhaps, may explain the apparent absence of the 

 prominences, because practically the lower part of the 

 corona was itself made up of them. 



"We have not, of course, any detailed information with 



regard to the results achieved by the other parties, but 

 when our own two English observers have obtained such 

 a rich harvest we are justified in concluding that the work 

 of the American and French parties has been equally 

 fruitful. In that case, the trouble which has been taken 

 to secure the observation of this eclipse, which took place 

 at a greater distance from home than any previously ob- 

 served, will have been entirely justified. 



" As we have said, the results of the other parties will 

 take some time to reach us, but at least we may be sure 

 of this — that the Americans, with their large experience 

 of eclipses and their trained observers, will have much 

 that is new and important to add to the results which our 

 own English party has achieved.'' 



It will be seen from what we have stated and from the 

 extracts which we have made from the Times that the 

 Royal Society and the Solar Physics Committee of the 

 Science and Art Department are to be entirely congratu- 

 lated on the result of their labours, and there is little 

 doubt that in this, as in former eclipses, not only shall we 

 have a most important explanation and verification of 

 previous observations, but fresh questions will be raised 

 to be included in future programmes. It should also be 

 said that the indifferent success telegraphed in some cases 

 may refer to the number of photographs taken rather 

 than to the quality of some of them. It is not likely, for 

 instance, that some photographs were not obtained of the 

 bright lines before and after totality by means of the 

 Rutherford grating, and if only two have been obtained 

 at different epochs the greatest possible value must be 

 attached to them. 



The telegram does not state whether the observers 

 have yet reached San Francisco, but in all probability 

 they have, in which case they may be expected home in 

 three weeks' time. 



THE FERNS OF INDIA 

 Handbook to the Foils of British India, Ceylon, and the 

 Malay Peninsula. By Col. R. H. Beddome, F.L.S., 

 late Conservator of Forests, Madras. Large 8vo, 500- 

 Pages, with 300 Illustrations. (Calcutta : Thacker and 

 Spink ; London : W. Thacker and Co., 1883.) 



Ft R something like the last thirty years Col. Beddome 

 has made a special study of Indian ferns under 

 very favourable circumstances. Holding as he did till 

 about a year ago the post of Chief Resident Conservator of 

 the forests of the Madras presidency, he was brought into> 

 daily contact with them in his official work, and at his 

 home at Ootacamund he formed a large collection of 

 them under cultivation, many of which have never 

 reached England in a living state. About 1S60 he com- 

 menced his well known series of illustrations of Indian 

 ferns, in continuation of Wight's " Icones," in which the 

 ferns had been entirely neglected. His plates, like 

 Wight's, were in quarto, uncoloured, and were mainly 

 executed by native artists. His "Ferns of Southern 

 India and Ceylon " contains plates of 271 species and 

 varieties, and was issued in parts and finished in 1863. 

 His " Ferns of British India," which was devoted to the 

 species not found in the southern presidency, contains 

 345 plates and was finished in 1868. In 1876 he published 

 a supplementary part, containing 45 additional plates, 

 thus raising the total number to 660, and a revised 

 general catalogue and su.nmary of genera and species. 



