Ih. II. < 'ojM>liin<l. Oli*'rrntin,i.i nf' f/n ,W</- /,'///// 



totality stnick me as 1eing very continuous, for I did not see the 

 K 1174 ring. In common with all other observers, I was stnick lv 

 the extreme brightness and the red colour of Mercury some 2 pre- 

 ceding the Sun, while near the zenith Venus blazed in the purest 

 white. 



Turning to the photographic results, three successful negatives of the 

 prominences and the corona were obtained with the 40-foot, with 

 exposures of 5"-0, 18 -6, and 3"-0 respectively. On the whole, the 

 long exposure gives the best picture ; in the original negative the 

 light of the great equatorial streamers can be traced to a distance of 

 alxmt one solar diameter from the moon's limb, while the detail of the 

 shorter streamers is shown with considerable precision. The short 

 exposures naturally bring out the shorter rays that are to some extent 

 lost in the brightness due to the long exposure. 



There are also twenty-four spectrograms taken with a direct-vision 

 prism drawn in front of the object glass of the 40-foot. Of these, two 

 groups of ten each were secured, one set as totality was coming on and 

 the other immediately after it had ended. They were taken on plates 

 measuring 8 inches by 16 inches, so arranged as to be moved trans- 

 versely in the plate-holder between each exposure. The " height " of 

 each spectrogram is 0'3 inch, while an interval of inch is allowed 

 between the different pictures. The remaining four spectrograms were 

 taken after totality with the 40-foot acting as a prismatic camera. 

 The two earlier ones show H, K and other lines extending beyond the 

 continuous spectrum, while the two last are of little interest except for 

 finding how long after the end of totality it is possible to obtain useful 

 spectrograms. 



In developing these plates, and in making the copies and slides* from 

 them, we had the advantage of the skilful assistance of Mr. John 

 Banks, photographer, of Edinburgh. 



McPherson's position inside the dark room of the 40-foot gave him 

 the unique opportunity of watching the actual image of the sun's 

 appendages as it imprinted itself on the sensitive films. At the time 

 of making the exposure of nearly nineteen seconds at mid-totality he 

 describes the picture as comparatively dark very little of the corona 

 being visible ; the larger prominences were, however, noticed, although 

 they were not nearly so bright as afterwards. In the last exposure, 

 near the end of totality, the prominences appeared of a bright flaming 

 red colour, and the picture on the plate was altogether a splendid 

 sight. Mr. McPherson was watching the prominences under the 

 impression that there were still five seconds to spare, as the time- 

 keeper at the metronome was counting seventy, and we expected the 

 eclipse to last seventy-five seconds, when all at once a sudden increase 



* The best of these slides, as well as contact copies of the larger negatives, were 

 exhibited at the meeting. 



