WINDS AND STORMS, 
461 
exclusively to the summer months. During the winter, Messrs. 
Lewis and Clarke, at the mouth of the Columbia river, had long con¬ 
tinued gales from the south-west, and deluges of rain. The violent 
winds that prevail at Cape Horn are not accurately from the west, 
hut from between the west and south.” Cook’s voyages into the high 
latitudes of the southern hemisphere being made when the sun was 
in the neighbourhood of the southern tropic, cannot be referred to, 
as affording information of unquestionable accuracy respecting the 
winds that prevail in those seas. 
IV. Thunder storms generally commence between mid- day and 
sunset, and move from west to east. 
Such persons as have paid any attention to the changes of the 
weather in this country, must be well aware that our thunder storms 
begin in the after part of the day, and move from west to east. Thev 
sometimes occur at night, but seldom after midnight. The direction 
of their motion does not appear to depend upon the predominance of 
the westerly over the easterly winds, being much more constant and 
uniform than that predominance; but to be a result and a proof of a 
commotion excited in the atmosphere at the time of their formation, 
and of a rush of the air from the west towards the east, in consequence 
of some new impulse just then communicated. The author of the 
article “Thunder, ” in the Encyclopedia Perthensis, states, that along 
the eastern side of the island of Great Britain, it is more frequent in 
the month of July than at any other time of the year, which he at¬ 
tributes to the circumstance that a wind from the west then succeeds 
to the east wind that had prevailed from April to the end of June. “ For 
the most part, however, the west wind prevails, and what little motion 
the clouds have is towards the east, whence the common remark in 
this country, that thunder clouds move against the wind. But this is 
by no means universally true, for if the west wind happen to 
be excited by any temporary cause before its natural period when 
it should take place, the east wind will often get the better of it, 
and the clouds, even though thunder is produced, will move west¬ 
ward.” 
Of the remarkable thunder storms experienced in England 
from the year of the foundation of the Royal Society down to 
1800, and noticed in the Philosophical Transactions, there are 
about thirty five. Of these, the beginning of twenty seven was 
between noon and mid-night, generally about three or four o’clock 
