Page:Proceedings of the Royal Society of London Vol 69.djvu/250

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The general darkness during totality was greater than that in India, 1898, and in Algiers in 1900, but not so much greater as was anticipated from the great length of duration of totality. No integrating photometer was used. Lamps and candles were provided in case of need, but they might have been dispensed with except for one adjustment.

FIG. 2.

The figure shows, by contour lines of equal brightness, the position of the two bright patches of incandescent " coronium " seen in the corona.

During totality I noted several times an uncoloured ring of light round the moon. It was evidently of terrestrial origin in fact, a ring such as apart from an eclipse would be described as a " corona." The radius of the ring was estimated as about 1 or 1^. The equatorial streamers of the true solar corona were estimated as being visible not further than a quarter of a degree from the moon's limb, being then lost in general diffused light. The peculiar feature about the ring, as a phenomenon of diffraction due to the small particles of water forming the cloud to which it was without doubt due, was that the maximum of brightness appeared to be in the ring itself rather than near its centre. After totality colours again appeared in it, but I did not note nor can I recall the diameter of the rings.