504 Scientific Proceedings, Royal Dublin Society. 
times the apparent height of the mountain, and extending as high 
again, a perfectly distinct blackish or grey haze subtending the 
angle of vision or about 30 degrees on a horizontal and vertical 
plane. There was nothing resembling it to be seen in any other part 
of the heavens, and the summit of Snowdon was perfectly clear. 
Such appearances in Ireland and Scotland have been noticed at 
much lower elevations, and they arise from manufacturing opera- 
tions in the neighbourhood of Glasgow, Belfast, or Dublin. 
Down the Clyde, with an easterly wind, they have been seen as 
a thick dry haze to extend to Gourock and Dunoon. Occasionally 
over the sea a haze from steamer smoke is seen, but as a rule it 
lies much lower than the smoke of towns. Fume from the 
Bessemer process and from ferromanganese works contains chiefly 
iron and manganese, with very little, if any, lead; but where 
such fume can ascend, so also may the lead fume. Other instances 
of the transference of dust, soot, and fumes may be cited. Thus, 
on January dth, 1901, with avery gentle easterly wind and a — 
cloudless blue sky, the fume and smoke from the alkali district 
of Runcorn and Widnes, with the smoke also of Liverpool, was 
very distinctly observed from Holyhead to be carried out far into 
the St. George’s Channel, at no great altitude, and descending 
apparently to not very far above the surface of the water. It 
presented the appearance of a reddish brown haze, and was not 
like that of steamer smoke, which is black or grey. It was 
evidently dry dust resulting from manufacturing operations 
carried on in the well-known industrial centres of Cheshire and 
Lancashire. The smoke of London may be observed high in the 
atmosphere as soon as one passes the Chiltern Hills, at or about 
Leighton Buzzard, when travelling southwards. The smoke of 
Alexandria and of the Vale of Leven is carried up Loch Lomond, 
and deposited upon the bracken on the western side of the Loch 
below Luss at a height of about 1000 to 1200 feet. 
On January 7th, 1901, in Dublin and the district to the east of 
the city, the sky was overcast but without cloud, and there was a 
light current of air moving from the east, but no sign of fog near 
the Harth’s surface. On the following day we received accounts 
of dense canopies of fog in London, and of similar atmospheric 
conditions in other parts of England. It appears, therefore, more 
than likely that this dry dust, smoke, or fume is carried in a body 
