398 Meteorological Observations , 



METEOROLOGICAL OBSERVATIONS. 



To Mr. Tilloch. 



Sir, xxn account having appeared in several of the daily 

 newspapers, of a large meteor seen in the neighbourhood 

 of London in the evening of Thursday the 7tn instant, I 

 proceed to communicate to you such particulars relating to 

 it, as I have been able to collect from several persons who 

 saw it at Hackney. According to their account it appeared 

 about five minutes before nine o'clock in \he north, and 

 moved in a direction to the west: its motion was not re- 

 gular in a straight line, nor in a uniform curve; but it leaped 

 forward by successive jerks, describing a sort of undulated 

 track ; and they represented it as being of considerable mag- 

 nitude : after being visible for some seconds, it apparently 

 entered a cloud and disappeared. The circumstance of its 

 peculiar motion is, I think, worthy of record ; and if any 

 of your readers should have made observations on it, at any 

 considerable distance from London, I should be obliged to 

 tbem to communicate the same in the Philosophical Ma- 

 gazine. 



In investigating the causes of these luminous accensions, , 

 I think we may perhaps be assisted by observinsi and noting 

 down accurately the peculiarities remarkable in the different 

 kinds of them, which from time to time appear. The 

 very large sort, which occasionally are seen, such for exam- 

 ple as that memorable meteor which happened on the ISth 

 of August 1783, or the large one rccentiv observed at Ge- 

 neva, are not numerous enough to admit of being arranged 

 under any general description ; besides that there are pecu- 

 liarities in ail of them, whereby each differs from evcrv other. 

 But the smaller kind which appear in common seem to me 

 to be of three distinct varieties, and appear to derive their 

 particular character from the kind of weather in which they 

 happen. 



The most common sort are those very small meteors 

 which are prevalent in clear frosty winter nights, and in- 

 deed in summer also when there are dry easterly winds and 

 very clear skies. They have very much of the appearance 

 of the real sta'-s, and have probably from this circumstance 

 derived their vulgar name : they leave little or no train 

 behind them, and shoot along in straight lines generally 

 obliquely downward, but sometimes horizontally. 



The second kind are larger and more brilliant, and ge-* 



nerallv 



