ANTHELIA AND CORONAS. 
277 
only appeared at intervals, were very faint; and 
the colours of No. 4. merely luminous shades of 
grey. Having carried a pocket sextant with me 
to the mast-head, I took some pains to determine 
the diameters and breadths of the different coro¬ 
nas ; but I found the reflections in the glasses of 
the sextant so faint, that they could not be mea¬ 
sured in the ordinary way. I therefore hove the 
ship to, and waited until a small lump of ice, 
floating on the water, came in a line with the out¬ 
er circle. This being a conspicuous object, I 
brought its image in the sextant, in contact with 
the glory in the centre, and consequently deter¬ 
mined the radius of the circle. The following re¬ 
sults were thus obtained. Radius of the circle 
No. 4.,—inner edge, 36° 50'; middle, about 38° 50'; 
outer edge, about 41° or 42°; breadth of the circle, 
about 5°. The greatest semi-diameter of the pri¬ 
mary rain-bow, with which this circle might be fair¬ 
ly compared, is 42° 37'; so that it is not improba¬ 
ble but this might have proved the same, had it 
been sufficiently defined to admit of accurate mea¬ 
surement. The semi-diameter of No. 3., was, by 
estimation, about 6° 30'; of No. 2., the exterior li¬ 
mit by measurement, about 4° 45'; and of No. 1., 
by estimation, from ]a° to 2°. The suu’s altitude at 
this time was 35° 42', consequently, the depression 
of the glory below the horizon the same. The 
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