TOTAL ECLIPSE OF THE SUN, JANUARY 22, 1898. 
165 
secured on to a flat board resting on three packing cases filled with stones, the 
packing cases standing on solid cement bases. 
“ Three exposures were made—- 
1st, 15 secs.127-112 
2nd, 90 „ .... 107-17 
3rd, 8 ,, .... 12-4 
“ This instrument was worked by myself and two assistants, one as exposer and 
one as timekeeper.” 
To this it may be added that the instrument had two prisms each, with an angle 
of 60'^, and faces 2|- X 5 inches, and they were set to minimum deviation for H^. The 
focal length of the collimating lens was 72 inches, and its effective aperture 2|- inches, 
so that a part of the sky, a little more than two degrees in diameter, would be 
embraced. 
Light was reflected into the slit by the mirror of a 12-inch coelostat kindly lent to 
the expedition by Dr. A. A. Common. 
The collimator being horizontal, it was set to the bearing S. 70° E. corresponding 
to the bearing of the sun at rising. Some little trouble was experienced at first with 
the driving clock of the coelostat, but owing chiefly to the skill of Engineer Mounti- 
FiELD and W. Holme, s, engine-room artificer, it was made to work very satisfactorily 
a few days before the eclipse. 
The adjustments of the instrument were thoroughly tested by Mr. Fowler on the 
morning of the eclipse during the partial phases, and successful photographs were 
taken ; but although the three exposures were duly made during totality, no results 
were secured. 
There is reason to fear, however, that the slit was closed before totality, so that we 
are left in doubt as to the efficiency of a photographic integrating spectroscope. 
The Coronagrapli. 
Staff-engineer Kerr reports as follows :— 
“ During totality five photographs were taken by this instrument. Throughout 
this time the plates were inserted and exposed continuously, the insertions being as 
rapidly effected as possible. 
“ Commencing at totality, the first exposure lasted 5 seconds, the second was a 
‘ snap,’ the third lasted 75 seconds, the fourth occupied 22 seconds, the fifth and last 
was a ‘ snap ’ made at 5 seconds before the end of totality. 
“ Attention to instrumental details precluded observation of the totality phase of 
the eclipse before and after taking the third photograph, but, during the liberal 
interval afforded by the comparatively long exposure for the latter, a good view of 
the eclipse was obtained.” 
