of Edinburgh^ Session 1862 - 63 . 107 
tlie burning gas, as it lies horizontally and can be more easily acted 
on by a flame issuing from it. 
“ At D the pipe dips vertically about eighteen inches. 
“ It is evident that the vertical length of pipe DE would not 
be readily melted by the strong flame burning at D. 
“ The boarding and lead at B, immediately over D, would there- 
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. 
‘‘ H.’’ 
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 aff'air, 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 
These globules had very imperfect adhesion, and had mostly dropped off 
when the plate was presented to the Koyal Society ; but some few of the more 
distant ones still remained, and all the others had left marks, usually of a 
yellowish colour, showing their former positions, sizes, and shapes. 
