405 
Scientific Intelligence.— Hydrography. 
served in Poland, in the month of December 1806. The win- 
ter was remarkably mild, no snow had fallen, but storms were 
frequent, One evening about 9 o’clock, after a violent gust of 
wind, the night became so dark that riders could no longer see 
even the heads of their horses, and so violent a storm arose that 
the horses were forced to halt ; but their ears became speedily 
luminous at the tops, as also all the long hair of the body, with 
exception of that of the mane and tail. All the metallic ends 
of the harness became luminous, as if they were covered with a 
swarm of luminous worms. The whiskers of M. Bourdet, and 
that of the other cannoneers, also shone ; but neither the eye- 
brows nor hair became luminous. This appearance continued 
as long as the gust of wind ; that is, about three or four mi- 
nutes. As soon as the wind ceased, the luminous appearances 
vanished, and a violent shower of rain fell 
4. Remarkable Whirlwind . — On the 6th July 1823, at 1 h. 
35 m. p. m., in the plain of Assonval, a village situated six 
leagues WSW. of St Omer, and an equal distance from Bou- 
logne, the labourers were obliged to quit their work on account 
of the darkness, and from the dread of a tempest with which 
they were threatened. Clouds coming from different points ra- 
pidly collected over the plain, and presently united so as to form 
a single vast cloud which covered the whole horizon. A mo- 
ment after, there was seen to descend from this cloud a dense 
vapour, having the bluish colour of sulphur in a state of com- 
bustion : it formed a reversed cone, the base of which was con- 
nected with the cloud. The lower part of the cone, which de- 
scended upon the earth, turning round with considerable quick- 
ness, presently formed an oblong mass of about 30 feet, detached 
from the cloud. It rose making a noise similar to that of a large 
bomb-shell on bursting, and leaving in the earth a pit in the 
form of a circular basin, from 20 to 25 feet in circumference, 
and from 3 to 4 in depth at its middle. At the distance of 
scarcely a hundred yards from the point of departure, and di- 
recting its course from west to east, the whirlwind broke down 
the hedge of a dwelling house, overturned a barn, and gave the 
house, which was more solidly built, a shock, which the farmer 
compared to that of an earthquake. It had, in breaking the 
hedge, torn asunder and carried off the tops of the strongest 
