Fuly 22, 1886 | 
NATURE 
273 
Transit of ‘Transit of 
Date 1886 6 Urszx Minoris Polaris 
Ire Th 5 Is oils Ge 
August 14 8 35 46 ae 15 43 24 
15 8 31 49 eS I5 39 28 
16 8 27 52 £5) 35133 
17 S 23 55 15 31 37 
18 8 19 58 I5 27 41 
19 Selous I 15 23 46 
20 812 4 15 19 50 
21 Sasi, a I5 15 54 
22 Saeae lil ao: I5 11 58 
23 8 o 14 oo iy {3 1 
24 7 50 17 os Mey nd 
25 7 52 20 ae I5 0 12 
26 7 48 23 oe 14 56 15 
27 7 44 20 600 14 52 20 
28 7 40 30 600 14 48 24 
29 TBE OS oe 14 44 28 
H LEonis 
e 
e 
YY Leonis 
1 Leonis 
6 Leonis 
@ @Leonis ; 
Ory i X Leonis 
e 
ULeEonis 
BLEonts 
3 e 
HOKIZON 
Diagram of configuration of stars and planets during the total solar eclipse, 
1886 August 28-29, for Grenada. V = Venus; Mr = Mercury; 
Ma = Mars; J = Jupiter; S=Saturn; U = Uranus. 
We reprint from Sczezce the following paper by Mr. J. 
Norman Lockyer :— 
In order to obtain the greatest amount of assistance 
from observations of the eclipsed sun, it is necessary to 
consider in the most general way the condition of solar 
inquiry at the time the observations are made. If any 
special work commends itself to those interested in the 
problem,—work which may be likely to enable us to 
emphasise or reject existing ideas,—then that work should 
take precedence of all other. 
Next, if the observers are sufficient in number to under- 
take other work besides this, then that work should be 
arranged in harmony with previous observations ; that is, 
the old methods of work should be exactly followed, or 
they should be expanded so that a new series of observa- 
tions may be begun in the light and in extension of the 
old ones. 
In my opinion, and I only give it for what it is worth, 
the three burning questions at the present time —questions 
on which information is required in order that various 
forms of work may be undertaken to best advantage 
(besides eclipse-work)—are these :— 
(1) The true constitution of the atmosphere of the sun. 
By this I mean, Are the various series of lines of the same 
element observed in sunspots, e.g., limited to a certain 
stratum, each lower stratum being hotter, and therefore 
simpler in its spectrum, than the one overlying it? and do 
some of these strata, with their special spectra, exist high 
in the solar atmosphere, so that the Fraunhofer lines, re- 
represented in the spectrum of any one substance, are the 
result of an integration of the various absorptions from 
the highest stratum to the bottom one? This view is 
sharply opposed to the other, which affirms that the 
absorption of the Fraunhofer lines is due to one unique 
layer at the base of the atmosphere. 
I pointed out before the eclipse of 1882 that crucial ob- 
servations could be made during any eclipse, including 
the time both before and after totality. I made the obser- 
vations: they entirely supported the first view, but I do 
not expect solar inquirers to throw overboard their own 
views until these observations of mine are confirmed ; and 
I think one of the most important pieces of work to be 
done during the next eclipse is to see whether these obser- 
vations can be depended upon or not. 
One observer, I think, should repeat the work over the 
same limited region of the spectrum, near F ; another 
observer should be told off to make similar observations 
in another part of the spectrum. I have prepared a map 
of the lines near E, for this purpose, showing those bright- 
ened on the passage from the arc to the spark, and those 
visible alone at the temperature of the oxy-hydrogen flame. 
Whereas some of the spark lines will be seen seven 
minutes before and after totality as short, bright lines, 
some of the others will be seen as thin, lone lines just 
before and after totality. We want to know whether the 
lines seen at the temperature of the oxy-hydrogen flame 
will be seen at all, and, if so, to what height they 
extend. 
(2) The second point to which I attach importance is one 
which can perhaps be left to a large extent to local 
observers, if the proper apparatus, which may cost very 
little, be taken out. 
With this eclipse in view, I have for the last several 
months gone over all the recorded information, and have 
discussed the photographs taken at the various eclipses 
in connection with the spots observed, especially at those 
times. 
The simple corona observed at a minimum with a con- 
siderable equatorial extension -(twelve diameters, accord- 
ing to Langley), the complex corona observed at maximum 
when the spots have been located at latitudes less than 
20°, have driven me to the view, which I shall expand on 
another occasion, that there is a flattened ring round the 
sun’s equator, probably extending far beyond the true 
atmosphere ; that in this ring are collected the products 
of condensation ; and that it is from the surfaces of this 
ring chiefly that the fall of spot-forming material takes 
place. 
If we take any streamer in mid-latitude, we find, that, 
while the spots may occur on the equatorial side of it, none 
are seen on the poleward side. I regard the streamers, 
therefore, like the metallic prominences, as a sequel to the 
spot ; and there is evidence to suggest that a careful study 
will enable us to see by what process the reaction of the 
photosphere*and underlying gases produced by the fall of 
spot-material tends to make the spot-material discharge 
itself in lower and lower latitudes, as the temperature of 
the sun’s lower atmosphere gets enormously increased. 
The observations of Profs. Newcomb and Langley 
at the minimum{of 1878, on the equatorial extension, are 
among the most remarkable. Prof. Newcomb hid the 
