“Fie 
ey 
348 History of Astronomy for the Year 1805., 
tore up trees, and unrgofed houses. Hitherto Thad not been 
able to ascertain the cause; but my journey to Lyons fur-_ 
nished me with an idea which might.be realized. M. Molet, 
an intelligent medical professor, found, from his notes, that 
it thundered that day at Lyons. In passing through Sens I 
saw M. Soulas, who informed me that the wind had changed 
from north to south. The journals informed me that there 
was a dreadful storm at London on the same day. 
_ There_is, in my opinion, a mass of electrical clouds of 
§00 _myriametres in extent, the detonation of which had 
made an immense vacuum, and that the atr rushed with 
great violence to fill up this vacuum. I bad a confirmation 
of this on the 11th of January 1806. Some dreadful claps 
of thunder at Brest, Rouen, Chartres, and Ypres, produced 
tempests and hurricanes which overturned the chimneys,of 
the houses at Bourdeaux, ‘Besancon, Nancy, and Dijon. 
oud claps of thunder are very rare at this time of the year, 
~ but the south wind made it very hot ; the atmosphere was, 
rainy, the lower clouds were near enough to draw sparks 
from the earth to an extent of 60 mvriametres: there were 
also earthquakes at the same time. 
The hurricanes of the Isle of France and America, which 
are much more violent, require us to suppose the stormy 
masses much larger; but to these must be added water- 
spouts and submarine eruptions. 
M. Fiot, inspector-general of health, has sent me the 
results of the heights of the river, observed every day during 
the year 13. The mean state of the river this year was 1°34 
metres on the scale of the bridge of La Tournelle, stead of 
1-24, which | had found by a mean of eighteen years, 1777— 
1794. The year 13 has been considered as a rainy year, 
nevretheless there have becn years of 1°73, as 1787; whilst 
in 1803 we had only 0°59. This height is relative to the 
low water of 17193 but the river has sonretimes been lower 
by some centimetres. 
The Turi Academy has published its memoirs for 1804 
and 1805, in which there is a new barometer of M. Vassalli- 
Eandi, with heights measured in Piedmont. . 
M, Beraud, who for these thirty years past has made an im- 
mense 
