ON THE TOTAL SOLAR ECLIPSE OF AUGUST 29, 1886. 
303 
neighbourhood of the corona was sufficient to affect the whole plate ; but it did not 
on this occasion, and the images of the needle-points only appear on one plate, owing 
to a cause to be mentioned presently. This one plate is, however, quite sufficient to 
fix satisfactorily the orientation of the corona. I believe that the method could be 
rendered perfectly safe in future eclipses, and it is certainly more accurate than that 
hitherto used. 
2. Arrangements during Totality. 
Dr. P. F. Macleod, the resident officer of health in Grenada, and Mr. Murray, 
who accompanied the expedition as a naturalist, had offered their assistance during 
totality. This was gratefully accepted, and my best thanks are due to them. 
Mr. Murray undertook to screen the camera while the slides were being drawn or 
pushed in, so as to prevent a confusion of imtige due to shaking when the slides are 
touched. Dr. Macleod took charge of the slides before and after exposure, handing 
them as they were wanted, and placing them in a bag after they had been taken out 
of the camera. I had originally intended to take eight photographs, but had to 
change all arrangements suddenly when I saw the corona obscured by a cloud at the 
beginning of totality. As the brighter parts of the corona were faintly visible, and 
as I did not know whether the cloud would clear away in time, two photographs 
were taken, referred to in Mr. Wesley’s report as Plates 1 and 2. The exposure of 
these must have been about 15 seconds each. 
It is only in a very indirect way that I could, after the eclipse, obtain an idea of 
the various exposures given, and not much value is to be placed, therefore, on the 
numbers. I knew the time I intended to expose, but I generally closed the camera 
sooner, as I was always afraid of a fresh cloud coming on. 
The corona came out clearly while the third exposure took place. Instead of a 
plate, a piece of sensitized paper had then been put into the slide, but the result was 
not good. 
Three further plates were taken with the corona clear, the last about 15 seconds 
before the end of totality. After the spectroscopic cameras had also been shut, 1 
intended to take out all slides. Unfortunately I loosened the wrong hook, and drew 
the shutter instead of the slide, but, noticing my mistake at once, pushed it back. 
That moment the Sun came out, and the last plate was partly spoilt, but parts of the 
corona show well, and it has been used in making out the details of the corona. The 
accident was fortunate, in so far as the image of the needles necessary for orientation 
came out very clearly owing to the illumination by the reappearing Sun. 
3. Results. 
Mr. Wesley, who has made a careful drawing of most of the recent eclipses, has 
described the corona as it is shown on the photographs on the present occasion, and I 
need not add anything to his remaiks. But I should like to draw attention to one or 
