154 Proceedings of Societies. 
fore be exposed to the flame of the gas for a much longer time 
than any part between A and B. And here we might expect what 
we find, a large piece of the boarding burnt, and the larger of the 
two holes in the accompanying pieces of lead. 
‘“ How the gas was at first ignited remains to be shown. 
ae 5 eas 
The above memorandum gives an excellent matter-of-fact de- 
scription of what chiefly remained to be seen at the time when 
it was written, but it does not mention what had much struck me 
several days previously, when I first caught sight of the small and 
neat oblong hole in the roof at A; and, on subsequently pulling 
up the leads, which at that time had not been disturbed at that place 
since the storm, I found the under surface of the metal, strangely 
burred and scored around the aperture, and also perceived small 
globules of melted lead, driven away apparently by some radiating 
force from the hole, until caught and jammed between the remain- 
ing uninjured lead and its wooden surface of support.* Neither 
does the memorandum account for the first igniting of the gas, 
but expressly says, that what may have caused that ‘“ remains to 
be shown.” 
This is in truth the most important part of the whole affair, and 
which I will now endeavour to describe. 
The evening of the 4th of February 1863 ushered in one of the 
most violent storms of thunder and lightning that has been ex- 
perienced in Edinburgh, and perhaps in most parts of Scotland, for 
many years, and its violence was all the more remarkable, inasmuch 
as the month of February is near the minimum of the year for 
electrical manifestations in the shape of thunder-storms. This point, 
not yet generally acknowledged, is indicated pretty certainly by the 
following numbers, extracted from the Registrar-General’s printed 
Reports for Scotland; they are, in fact, the deductions prepared 
for that officer at the Royal Observatory, Edinburgh, from the 
schedules of fifty-five observers of the Meteorological Society of 
Scotland, and give, for the means of three years, as follows :— 
| 
| Number of Stations | Mean Number of | 
at which Lightning Times at each 
was seen. | Station. 
| ot dei rea | 
ie SMUT: 6 cilaavel 34 4 ) 
te PODRORTN, otitis. L1 2 
| March. . . : | 42 3 
! 
* These globules had very imperfect adhesion, and had mostly dropped off 
when the plate was presented to the Royal Society; but some few of the more 
distant ones still remained, and all the others had left marks, usually of a 
vellowish colour, showing their former positions, sizes, and shapes. 
