TOTAL ECLIPSE OF THE SUN, APRIL 16, 1893. 
581 
VI. Forms of the Prominences. 
Monochromatic Images. 
The results obtained clearly indicate that the best possible way of photographing 
the prominences during a total eclipse, so as to show their forms, is to secure mono¬ 
chromatic images of them by means of the prismatic camera. In the pictures taken 
with the coronagraph in the ordinary way the prominences are apt to be submerged 
in the intense light of the lower corona. In some of the African photographs taken 
with the prismatic camera the definition is very fine, and the structure can be 
minutely investigated by enlarging the photographs. The group of prominences near 
the sun’s south pole shows a wealth of detail in most of the African negatives, as will 
be clear from the enlargement of the K image, which is reproduced in fig. 9. 
By isolating the portions of the rings of prominences and chromosphere which 
correspond to any particular radiation, the distribution of the corresponding vapour 
can be represented at any phase of the eclipse ; a composite photograph made up of 
two such isolated portions of rings, one as seen at the beginning and the other at the 
end of totality, indicates the distribution of the vapour throughout the chromosphere 
and prominences visible during the whole of totality. Fig. 10 is a copy of the K-ring, 
as built up from the African photographs Nos. 7'and 21, the light due to other radia¬ 
tions having been painted out. 
Fig. 9. 
Group of prominences near sun’s south pole, April 16, 1893. 
The ring is not complete for the reason that some parts of the chromosphere— 
namely, those in the neighbourhood of the points on the sun’s limb which are cut by 
a line perpendicular to the direction of the moon’s motion—were covered by the 
moon during the whole of totality. 
The various parts of the chromosphere and prominences have been numbered, as 
shown in the above diagram, for purposes of reference in the discussion of the 
photographs. 
