DR. C. B. PLOWRIGHT ON SOLAR HALO AND MOCK SUN. 
175 
likely that the number of days in which there is more or less fog 
has something to do with it. In order to see a solar halo the 
sun must not be too bright, otherwise the observer cannot look at 
it. On 25th May, 189-1, a fine solar halo was seen in Lynn. 
About 11 a.m. it was very readily seen by the naked eye; at 1.45 
it could be seen, but it was not then so bright as to have attracted 
general attention, in fact it had to be looked for. An hour later it 
could be seen only by looking for it through a smoked glass, and was 
obvious enough then, and could be seen late into the afternoon. 
On a subsequent occasion my friend Mr. L). C. Burlingham called 
my attention to a solar halo, but by the time he reached my house 
it could not be seen, except through a coloured glass, the brightness 
of the sun overpowering it. 
On the 22nd December, 1900, at about 1.45 or 1.50 p.m., my 
son, Mr. C. T. M. Plowright, and myself saw, as we were riding up 
Shouldham Thorpe Ilill, a very bright solar halo, which measured 
roughly 45° across. Owing to the low position of the sun in the sky 
at this season it did not form a complete circle, the lower third, or 
perhaps less, being invisible. In about fifteen or twenty minutes 
the halo gradually became paler, but from its zenith two curved 
streaks of light were projected upwards, forming what appeared to 
bo the commencement of a second circular halo above the lirst and 
arising from it. The diameter of this second halo was apparently 
much less than that of the first, but it never became sufficiently 
developed to measure, even approximately. At this time, 2 p.m., the 
two haloes wero like the symbol for the zodiacal sign Taurus (O). 
At the point where these two haloes touched one another a luminous 
area was now formed — the mock sun. It was 2° or 3° across, 
rounded, but not distinctly a disc like the sun itself. The haloes 
had by this time faded very considerably, but were still visible 
when looked for. The parhelion was plain enough, although it 
resembled a thin place in a cloud obscuring the sun rather than 
the sun itself. It certainly would have escaped observation had 
not the whole train of phenomena been watched. The parhelion 
was watched by ourselves, and Mr. Henry Hoft at his house at 
Shouldham Thorpe, for some fifteen to twenty minutes. In half an 
hour it was all but gone, but then came the final phase. From 
the sun, upwards and downwards, two beams of light extended 
vertically. These were widest where they started from the sun, 
