534 
Proceedings of the Koyal Society of Edinburgh. [Sess. 
After the storm was past, the electroscope discharged — electricity at the 
rate of 2 per min., ten minutes later it was + and discharging ten times 
per minute, at 7.30 it was — and discharging twenty times per minute. The 
electrification changed again at 8.40 to + and discharging eight times 
per minute. During the rest of the time the observations were made there 
was nothing calling for remark. The electrification remained steady + , and 
generally weak, only occasionally making slow discharges. 
Sunset Colours. 
There is nothing to report in this part of the investigation. No brightly 
coloured sunsets were observed either before or after the 19th. If any-’ 
thing they were finer before, but this may have been due to the condition of 
the clouds. The only thing worth recording was the appearance of a sun 
pillar on the evenings of the 23rd and 24th, shortly after the sunset. Though 
that phenomenon took place about the time the high dust-readings were ob- 
served, yet it probably had no connection with the comet, as it is often seen 
under ordinary conditions. I was fortunate in securing a colour photograph 
on a Lumiere plate of the sun pillar on the 23rd, but failed with the one on 
the 24th, which was not so distinct, and my lack of experience did not 
guide me to the correct exposure of the plate to catch the faint colour. 
It must be admitted that the result of this investigation has been most 
unsatisfactory. There is not sufficient evidence to convict the comet of 
having in any way affected our atmosphere, and I think all of us who have 
been searching either for solid or gaseous parts of the tail have to admit 
that our visitor has not bequeathed a lock of its tail to any one of its 
admirers. 
The large amount of dust observed in the air on the 24th and 25th, and 
the doubtful source of it, have suggested that it might be worth while to 
continue dust observations for some time. If the tail of the comet has 
added any dust to our atmosphere, it will by this time be getting pretty 
well mixed up with the air at all elevations, and will thus enable me to 
make observations at Falkirk in the method described in Proc. Roy. Soc. 
Edin ., vol. xx. 
