Au.ii-sT 1, 1900.] 



KNOWLEDGE. 



177 



the 1S9S Eclipse, now two years and a baJf old, should 

 by this time be in a very complete state of discussion. 

 It is much to be regretted that a little more speed was 

 not made so that they might have been in the hands 

 of astronomers before their stalling for the late eclipse. 



6. PoL.\Riscopic Photogr.vphs. — To Professor Turner 

 in 1S9S we owe the revival, as an it<?ni of eclipse pro- 

 grammes, of the taking of polariscopio photographs of 

 the coi-ona, most successfully carried out by, and under 

 the direction of. Professor A. W. Wright in 1878. 

 This work Professor Turner, in conjunction with Mr. 

 Xewall, renewed in the late eclipse, and it is to be 

 hoped the success they attained will prevent it being 

 again dropped, for it is to be borne in mind that at 

 present we have only polariscopic photographs froin 

 minimum coronae, and it is a matter of great importance 

 to ascertain whether the intensity and distribution of 

 the polarization vary at different parts of the sun-spot 

 cycle. 



7. Spectroscopic Observ.vtions. — Photographs of the 

 spectrum formed a most important feature of tlie pro- 

 gramme of all the official parties. Mr. Dyson at Ovar 

 had two large slit spectroscopes ; Sir Norman Lockyer 

 at Santa Pola had a prismatic camera of 20 feet focus ; 

 Dr. Copeland used a prism in fi'ont of his lens of 40 

 feet focus during part of the eclipse; Mr. Newall at 

 Bou Zarea photographed the " flash " with a slit spec- 

 troscope ; Mr. Evershed at Mazafram, as recently men- 

 tioned, had two prismatic cameras, one of them being a 

 reflector. All appear to have been most successful in 

 their work, but many months will necessarily elapse 

 before the photographs obtained will be measured, re- 

 duced, and published. It may be mentioned, however, 

 that Mr. Evershed's reflector photographs give the lines 

 with unexampled sharpness of definition from end to 

 end, and that Dr. Copeland claims to have secured the 

 spectrum in the ultra-violet so far as wave-length 3000. 



Amongst the independent observers it should bo men- 

 tioned that Dr. Downing, observing with an opera-glass 

 fitted by Mr. Thorp with a prismatic grating before the 

 object glass, found the combination work most admirably. 

 The special subject of his scrutiny was the diffusion of 

 " coronium " as evidenced by the shape of the green 

 coronal ring. This averaged about 100,000 miles in 

 height, but in one particular region it rose to a height 

 of 180,000. 



8. Shadow-B.*.nd Observations. — These api^ear to have 

 been made with special fulness and care at several 

 different stations. The results of these observations 

 have not yet been collected, but it may be mentioned 

 that Mrs. Arthur Brook, whose apparatus is shown in 

 the photograph, observing at Algiers noted the " bands " 

 rather as separate patches closely following each other 

 in longr wavering ranks. Mrs. Brook made obsei-vations 

 of a unique character on the " shadows " near the time 

 of third contact when Baily's Beads began to appear, 

 and she asserts that the " shadow patches " were then 

 of a materially different character from what they were 

 a few seconds later still, when the sun itself emerged 

 and the light v.'as stronger. As in India there is a 

 marked divergence of opinion at different stations as to 

 their directions of motion before and after totality. At 

 Algiers Mr. Brook says decidedly that the direction 

 before second contact was approximately the same as 

 after third contact. At Elche the observers say that 

 the second direction of motion was reversed. 



9. Naked Eye Drawings of the Corona. — Of these 

 the late eclipse has yielded an unprecedentedly large 

 supplv, of the average quality of which it is scarcely 



possible to speak too highly. It is a curious and un- 

 expected detail of evolution that not only is there a 

 progress in artistic ability and truth in the individual 

 through the means of his personal practice, but there is 

 also in the race. The same sort of thing has been 

 noticed before now in drawings of the surfaces of the 

 moon and planets. Men see more easily and depict 

 more faithfully, faint, dillicult or minute markings, than 

 was done fifty or a hundred years ago. Indeed the trend 

 towards uniformity has been so strong as occasionally 

 to draw forth sharp criticism, and hints of the effect 

 of bias. That could not bo the case here; drawings 

 made by observers separated from each other by scores 

 or hundreds of miles and having not the slightest means 

 of communicating with each other have by their resem- 

 blance borne tlie most striking testimony to the skill 



Fio. 2.— The llarb..! 



Algiers, live niiimfces before Totality. 

 Front n Pliolo Inj Miss Ehith Mauniikr. 



and fidelity of the artists. There has been a complete 

 absence of the grotesque and extravagant designs that 

 were common enough a generation ago. Some of the 

 drawings too were made with the most astonishing 

 rapidity, Miss Stevens', for example, already reproduced, 

 was the result of less than forty seconds devoted to the 

 scrutiny of the corona, and yet, — though not intended 

 to exhibit in particularity the details of the corona, — 

 it could be scarcely surpassed as a representation of the 

 general effect. This improvement is a matter for the 

 greater congratulation since it is manifestly due to 

 greater skill in the observer, and the observer must 

 always be more important than the instniment. The 

 improvement in the delineation of planetary surfaces 

 might well have been ascribed to the improvement of 

 telescopes, but that cause cannot enter in the case of 

 drawings of the corona made with the naked eye. 



10. Drawings with the Telescope. — This work has 

 been to a very great extent the special feature of the 

 late eclipse. In particular it is a subject for congratula- 

 tion that Mr. Wesley, whose skill as an artist is so well 

 known, and whose acquaintanceship with coronal forms as 

 shown on photographs is unapproached, was by the most 

 generous courtesy of M. Trepied put in possession of the 

 equatorial coude of the Algiers Observatory on the 

 occasion of the eclipse. " I think," said Mr. Wesley, 

 " I have had the most magnificent — though restricted- 

 view of the corona that ever mortal man had — something 

 to have lived for." Mr. Wesley made a study of and 

 sketched the entire corona within his field of view, which 



