894 Transactions.— Miscellaneous. 
In 1777, 17th June, about noon, Messier states he perceived an im- 
mense number of black globules pass over the sun's disc. 
In 1788 there was a dry fog, and many attributed it to volcanic 
action, and it is well known that in February that year fearful 
earthquakes in Calabria took place, followed by a long list of 
voleanie eruptions in the world. 
In 1881, there was an extraordinary dry fog, which excited public 
attention throughout the world. It appeared on the coast of 
Africa on the 8rd August; at Odessa, on the 9th August; in . 
South France, on the 10th August; at Paris, on the 10th 
August; New York, on the 15th August; Canton (China), at 
the end of August. This fog was so thick that it was possible 
to observe the sun all day with the naked eye, and without a 
‘dark glass; and in some places the sun could not be seen till it 
. was 15° or 20? high. At Algiers, United States, and Canton the 
sun's disc appeared of an azure blue, or of a greenish colour. 
Where the fog was dense, the smallest print could be read even 
at midnight. 
In 1878, of the dry fog which came on suddenly in June, it is 
recorded that it extended from the northern coast of Africa, 
over France, to Sweden, and over great part of North America, 
and lasted more than a month. Travellers found it on the 
summits of the Alps. Abundant rain in June and July, and 
most violent winds did not dissipate it; and in some places it 
was so dense that the sun could not be seen until it had 
attained an altitude of 12°; and throughout the day-time it was 
red and so dull that it might be looked at with the naked eye. 
The fog diffused a disagreeable odour, and the humidity ranged 
from 57 to 68, while in an ordinary fog it is 100. It had a 
phosphorescent appearance, and the light at midnight was 
compared to that of full moon. 
Here was exhibited a diagram (pl. xix.), drawn correctly to a scale of 50 
miles to an inch, showing the are (of 15°) of a circle whose radius was 6 feet 7 
inches, or a diameter of 18 feet 2 inches. The Himalayas were shown in their 
correct proportion; so was the smoke from Cotopaxi, estimated by Whymper, 
while on Chimborazo, at 40,000 feet; he saw, at 5:45 a.m. of the 80th July, 
1880, a dense column of smoke shot up straight into the atmosphere with 
prodigious velocity, which in less than one minute had risen 20,000 feet 
above the crater, giving the total height of 40,000 feet above sea-level. The 
dust, he goes on to state, fell on Chimborazo after six hours, and he esti- 
mated that each particle did not weigh the one-twenty-five-thousandth — 
(zsd00) part of a grain, and the finest were still lighter, 
i 
