







e here some admirable drawings, which I wiil show by means 
the Jamp, of the eclipse that was observed in 1851 by several 
‘onomers who left England in that year to make observations 
n Sweden. where the eciipse was visible. You must bear in 
‘mind that the drawings I shall bring to your notice were made in 
the same regior, at places not more than a few miles apart.* 
The first drawing was made by an observer whose name is a suffi- 
cient guarantee for its accuracy—I refer to Mr. Carrington—and 
when the sky was absolutely free from clouds. nthe next diagram 
you will see the coronais changed. The bright region round the 
_ sun is no loner limited to the narrow border of light round the 
_ dark moon, as seen by Mr. Carrington, but it is considerably 
expanded. The third gives still a greater extension, although 
that picture was drawn within a quarter of a mile of the place 
_ where Mr. Carrington’s was taken. And lastly, we havea draw- 
- ing made by the present Astronomer Royal, of that sameeclipse, 
| through a cirrostratus cloud as unlike Mr. Carrington’s as any- 
_ thing can possibly be. So that you see we began with a thin 
band of light about the moon, which would make the corona a 
few thousand miles high, and we end with a figure which Mr. 
_ Airy graphically likens to the ornament round a compass-card, 
_and which gives the corona a height equal to about once and a 
half the sun’s diameter. 
I will next bring before you some drawings made during the 
NATURE 
, and state the nature of the problems we had before us. I | see. This, then, we may look upon as the known ; now let us 

but in South America by two first-rate observers—one, M. Liais, | 
a French astronomer, who was stationed at Olmos, in Brazil ; 
eclipse of 1858, which was not observed in European regions, 
miles away in Peru. 
I will throw on the screen the appearances observed by these 
_ gentlemen, and I think you will acknowledge the same varia- 
tions between their results, as to degree, while in one case we 
_ get a perfectly new idea of the phenomena—a difference in 
_ Kind. I would especiaily call attention in the Olmos drawing 
_ to those extraordinary bundles of rays of wonderiul shapes, 
which you see are so much brighter than the other portions of 
the corona. Such forms have been seen in other eclipses, but 
thev are somewhat rare. The drasing made by Lieutenant 
Gilliss bears the same relation to that made by M. Liais as Mr. 
Carrington’s did to the Astronomer Royal’s ; so that we may 
say thar we not only get variations in the dimensions of the 
q 






















_a strange structure mtroduced now and then in our drawing in 
regions where absolutely no corona at all exists in the other. 
So much by way of defining the phenomena and giving an 
idea of the eye observations generally. 
Let me now attempt to show you how the phenomena observed 
vations, and by means of the polariscope and spectroscope. 
I.—TELESCOPIC AND NAKED-EYE OBSERVATIONS 
a.—A Partof the Coronais undoubtedly Solar 
The first use I propose to make of the telescopic and naked- 
eye observations of last year is to show you a photographic copy 
f an admirable drawing made by Mr. Brett, who, though unfor- 
tunate enough to see the sun only for a very short time, was yet 
sufficiently skilled to make good use of that brief period. This 
drawing will bring before you the fact that even when a large 
portion of the sun remained unobscured by the moon, Mr. Bzett 
was enabled to see a dim ring of light round the unobscured por- 
tion, which since the year 1722 has been acknowledged, beyond 
all question, I think I may say. to represent something at the 
sun. It was observed in 1722 round the uneclipsed sun, and in 
more recent times by Mrs. Airy in 1842, and by Rumker 13 minute 
before totality in 1860, not to mention other instances. There- 
fore we have one observation made during this eclipse, confirm- 
ing the old one, that in the corona there is a region of some 
small breadth at all events which is absolutely solar, and which 
it only requires a diminution of the solar light to enable us to 
* Mr. Carrington observed at Lilla Edet, on the Grota River. The 
_ Astronomer Royal observed at (.étrenbu:'g Tresecond drawing referred 
to was made by Pettersen. at Gdtteuburg; the third by a friend o! the Rev. 
T. Chevalli-r, at the same place and I might have added znotber by 
Fearnley, taken at Rixho:t, in which the corona is larger than in any of the 
others, The series is most instructive. See Mem. R. A. S. vol. xxi 
corona as seen at different stations, but that we furthermore get | 
the other, Lieutenant Gilliss, who was also there as a repre-enta- | 
tive of the American Government, and observed some thousand | 

in the last eclipse bear upon the results which had been pre- | 
viously accumulated by means of telescopic and naked-eye obser- | 
| the side at which the contact took place. 

feel our way gradually outwards. 
b.—Rays, or Streamers, are added at Totality 
The drawings made in all the eclipses which have been care- 
fully recorded bring before us quite outside this narrow, un- 
doubtedly su/ar region, observed before totality, as I have shown, 
and also by Mr. Carrington, and by Lieutenant Gilliss during 
totality in 1851 and 1858, extraordinary appearances of a different 
order. While in fact we have a solar ring from 2’ to 6’ high, 
we have rays of all shapes and sizes visible outside, in some 
cases extending as far as 4°, and in all cases brichter than the 
outer corona on which they are seen. the rays being different in 
different eclipses, and appearing differently to different observers 
of the same eclipse, and even at the same station. Here isa 
copy of a drawing made by M. Rumker of the eclipse of 1860, 
and I show it for the purpose of calling your attention to the 
fact that the two curious rays represented in it belong to a 
different order of things from those which we see in the rest of 
the corona From the beginning to the middle of the eclipse 
the east rays were the most intense. In the next drawing, which 
was made by the same observer, you ste something absolutely 
new; and now the western side of the corona is the most 
developed ; we have a new series of bright rays, and altogether 
it is difficult to believe that it is a drawing made by the same 
observer of the same eclipse. 
The third drawing is a representation of the same eclipse by 
M. Marquez, who observed with a perfection of minute care 
which has scarcely ever been equalled : I bring it before you to 
show that the rays he saw were altogether differently situated. 
We may conclude then that the rays, a though extremely definite 
and bright—as bright or brighter than the other portions of the 
corona which are visible before totality, they being zzwiszb/e before 
totality—appear different to different observers of the same eclipse, 
and to the same observer during different phases. 
c.—They Change from Side to Side 
I have already said that M. Rumker observed that from the 
beginning to the middle of totality the rays on the cast side of 
the sun were longest and brightest, and that from the middle to 
the end of totality the rays on that side of the sun where the 
totality ended were longest and brightest. 
We will now carry this observation a step further, by referring 
to three drawings made by M. Plantamour in the same eclipse, 
that of 1860. In the first drawing we have the beginning of 
the total eclipse as seen in the telescope; with the naked 
eye naturally we should get the sun disappearing at the east 
or left-hand side, the moon moving from west to east; 
in the telescope things are reversed, and we have it right 
instead of left: and here we have the same thing that M. 
Rumker observed, namely, that when the eastern limbs were in 
contact, bright rays (M. Plantamour saw three) were visible on 
When the moon was 
half way over the sun, “wo rays of reduced brilliancy were 
observed on that side, not necessarily in the same position as 
those first observed, but one of these has been abolished al- 
together; and on the other side of the sun, where totality was 
about to end, we have three rays gradually suggesting themselves : 
at the end of totality the rays visible at the commencement are 
abolished, and now instead of them and of those seen at the 
midéle of the eclipse, we have a bran new set of rays on the 
side of the moon from whence the sun is about to emerge. 
This observation I need hardly say is of considerable im- 
portance in connection with the f-ct that from the year 1722 
almost every observer of a total eclipse has stated that there is 
a large increase of brilliancy, and an increase of the size of the 
corona on the side where the sun has just been :overed, or is 
just about to emerge. 
Now, what was there bearing on this point in the recent 
observations? I have here three drawings, which, though 
roughly done, you will see are of great importance side by side 
with those of M. Plantamour. These are drawings which have 
| been sent in to the Organising Committee by Mr. Gilman, who 
lives in Spain, and who took considerable interest in the eclipse, 
and sent the results of his observations to England with the 
eclipse party when they came home; and it is of importance 
that you should see everything that Mr. Gilman has done, If 
you agree with this explanation of the square form of the 
corona, which was observed in Spain this year, it will explainl 
the quadrangular form observed in the corona in a good 
