RED PROMINENCES SEEN DURING TOTAL ECLIPSES OF THE SUN. 453 
subtended an angle of not less than 4°°5 on the moon’s limb ;* and its figure being 
irregular, the different observers may have estimated the position of points in it 
whose places varied considerably. 
Angles of Position of the Hook-Shaped Prominence. 
Angle of Position of Hook- 
OBSERVER. Station. Shaped Prominence from 
Sun’s North Point. 
Angles of Position of Spots 
near the Sun’s Limb. 



Dawes, | Ravelsberg, 282° 30° 88° (0! | 
Swan, Goteborg, ZO leaeeG (3\7/ a li, 288° 47’ 
Wichmann, Kénigsberg, 284 «0 86 40 287 7 


| 

It thus appears, that the discrepancies in the angles of position, cannot be 
explained on the hypothesis that the prominences are merely optical phenomena 
which appeared differently at different stations; for as great differences occur be- 
tween observations made at the same place, as between those made at stations 
widely removed from each other. It has also been seen, that where the angles 
of position were carefully ascertained, the places of prominences seen at distant 
stations, situated very differently in the moon’s shadow agreed closely; which 
is unfavourable to the idea that these objects are merely optical phenomena. 
2. On the Discrepancies in the Forms assigned to the Red Prominences by 
different Observers. 
The forms assigned by different observers to the red prominences exhibit, 
as might be expected, considerable diversity. The large hook-shaped promi- 
nence, to which reference has been so often made, was seen by every one, and 
engrossed a large share of attention. Several drawings of this remarkable object 
by different observers, are given in fig. 9, Plate XI.+ In its neighbourhood wasa 
‘small red spot, completely detached from the sun’s limb, and also a low promi- 
nence, neither of which was seen by all the observers. The drawings of this 
group differ in the occasional absence of the smaller detached prominence, or of 
the low one, and also in the form assigned to the hook-shaped prominence; but 
all agree in giving the latter a form curved in the same direction. Considering the 
hasty nature of the observations, the various powers possessed by different indi- 
viduals of delineating objects, and the fact that the drawings must either have been 

Md 
* In this estimation it is supposed that the breadth of the prominence was about two-thirds 
of its height, or 80”; an assumption which seems fully warranted by the drawings of the prominence 
given by most of the observers. 
{ The drawings of the hook-shaped prominence in fig. 9, are all taken from the Royal Astro- 
nomical Society’s Notice for January, with the exception of Mr Apre’s, which is enlarged from 
the plate accompanying his account of the eclipse in the Edinburgh New Philosophical Journal. 
VOL. XX. PART III. OF 
