500 Official Correspondence on the attaching of 



direction, or changes of direction, of the wind, with the 

 disposition of the clouds during the continuance of the 

 storm. The kind of the light observed, whether it was like 

 a sheet of flame, a darting spark, or a broken zigzag. The 

 character of the accompanying thunder-claps, whether ex- 

 plosive like the discharge of a large cannon, dull and rol- 

 ling, or sharp and rattling ; their duration, and its character- 

 istics, whether they succeeded each other rapidly, of the 

 same intensity, or gradually increased, or faded away, are 

 all important points for determination. The perception on 

 the discharge of lightning taking place of any shock, stroke, 

 or peculiar sensation of any kind, or of any strange taste 

 in the mouths of observers should be recorded, and the 

 exact time of the observation remarked. 



9 



6. Summary and Concluding Remarks. 



In conclusion, the observer should give a general sum- 

 mary of the case, of the inference it warrants, of its relations 

 to recorded opinions, with such other remarks as many pre- 

 sent themselves in connexion with the information he has 

 collected. It is impossible to be more specific on this point, 

 as each observer will discuss the instance he details with 

 more or less precision, according to the state of his own 

 knowledge of the general principles of electrical science. 

 The chief object, however, to be kept in view, is the col- 

 lection of carefully authenticated facts, minutely and faith- 

 fully detailed, and there will never be wanting those by 

 whom such facts will be rendered subservient to the true 

 progress of our knowledge on this most important branch 

 of physical science. 

 October 26th, 1840. 



