176 Prof. E. Mitchell on the Proximate 



that had prevailed from April till the end of June. " For the 

 most part, however, the west wind prevails, and what little mo- 

 tion the clouds have is towards the east, whence the common 

 remark in this country, that thunder clouds move against the 

 xolnd. 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 of- 

 ten get the better of it, and the clouds, even although thunder is 

 produced, zoill move westward.'" That the most common and 

 natural course of thunder-storms in that country is from west to 

 east, is therefore very apparent. 



(c.) Of the remarkable thunder-storms experienced in Eng- 

 land, from the year of the foundation of the Royal Society down 

 to 1800, and noticed in the Philosophical Transactions, there 

 are about thirty-five, the time of whose commencement, or in 

 general of their occurrence, is either distinctly stated or clearly 

 indicated in the abridgement by Hutton, Shaw, and Pearson. 

 Of these, the beginning of twenty-seven was between noon and 

 midnight ; generally it was about three or four o'clock in the 

 afternoon. One lasted all day, and the remaining seven were 

 in the morning. The direction of twelve is given. Two came 

 from the south, three from the eastern, and seven from the 

 western quarter. 



If the wind blow for a great length of time, or frequently at 

 intervals, from a particular point in any country, the fact will 

 be likely to be noticed by the traveller who may happen to be 

 upon the spot, and stated in his journal ; whilst the direction of 

 the gust during a storm, in which he may be involved, will be 

 altogether neglected. For this reason it is more difficult to fur- 

 nish proof that thunder-storms follow a particular course, than 

 to estabhsh the prevalence of certain winds in given latitudes. 

 It is but reasonable that this should be borne in mind, if the 

 evidence adduced in establishing our proposition should not be 

 regarded as in every respect satisfactory. The bare silence of 

 an Englishman or inhabitant of the United States, in regard to 

 the quarter in which a thunder-cloud rises, furnishes ground for 

 believing that it is the same as in his own country. Many sources 

 of information and argument, which would willingly have been 

 consulted, are not at hand. 



{d.) Dr Young, giving the substance of a paper by Longford, 



