NOTES ON PLATE EXPOSURES, 191 
Table J, Plate No. VI. 

ie Exposure. Remarks as to Light. General Remarks. 
oO. { 
1 | 5 minutes | Dull light, far removed | To bring out as much 
general detail as possible 
over the whole field. 

2 | 15 seconds | Bright light, close Printed whole of 
negative. 
3 | 30 seconds | Bright light, close Outer portion of cor- 
jona blacked out—shows 
up polar streamers well. 
4 |l minute | Bright light, close More of corona blacked 
out, carries detail of 
corona further in. 
5 | 2 minutes | Bright light, close Polar streamers close 
in, prominences showing 
well through inner 
corona. 

6 | 4 minutes | Bright light, close Prominences only 
showing. 



To examine these six prints is to see all that the nega- 
tive can give; one has the effect of six different negatives, 
each giving the best exposure for one particular portion 
of the corona. Six prints were taken from each of nega- 
tive I and VI, whilst from plate III, three were all 
that were desired at present, (two, of maximum and mini- 
mum exposure respectively, and one of intermediate 
exposure). 
The photographs illustrating this paper correspond to 
prints 1, 3, 4, and 6 of Table I. No enlargement work has 
so far been carried out with this set of negatives. 
The same process has been applied to the photographs 
taken with the aeroplane camera; in addition, a number 
of enlargements have been made which are quite instruc- 
tive. A composite inner and outer corona picture is being 
made from one of the aeroplane camera plates enlarged 
