On the Effects of Lightning 247 



rock. It is stated that in rock, occasionally, a sort of honey- 

 comb condition is produced, rather than single tubes. 



The Immediate Concomitants of the Striking of Trees by Lightning. 



It is not very often that the opportunity occurs, to good 

 observers, for witnessing the effects of a lightning flash upon 

 a near object, such as a tree. What happens is usually of 

 less than momentary duration, and too startling to permit of 

 accurate realisation. There may also be a dazzling and 

 almost blinding light. We may assume that it is only 

 when the current is received by a very good conductor that 

 it fails to produce detonation and more or less shattering. 

 In the case of trees which contain moisture, the heat must 

 produce steam, by the expansion of which much of the detach- 

 ment of bark, splitting of wood, &c, is, probably, caused. 

 With this heated steam no doubt a body of luminous 

 vapour becomes visible, and this phenomenon may last much 

 longer than the flash itself. An occurrence of this kind 

 was witnessed a few weeks ago from the gardens of the 

 Haslemere Rectory. A considerable company was assembled 

 at a parish meeting on the lawn one afternoon. The sky 

 became suddenly black with clouds, so that a condition of 

 partial darkness was caused. Suddenly a tree 1 on a hillside 

 opposite was seen to be in a blaze of light. It was thought 

 by some observers that flames spread into adjacent bushes, 

 but in the torrent of rain which instantly followed the whole 

 was immediately extinguished. Subsequent examination 

 showed that there were no bushes near the tree, and that the 

 tree stood almost alone. All who saw the occurrence agree 

 that there was an appearance of a fire and that it was of longer 

 duration than a mere flash. So little conspicuous was the 

 amount of damage done that one or two search parties failed 

 to discover the tree which had been struck. It was not until 



1 This tree stands in a valley on what is known as the Swan Barn Farm, 

 and can be examined by any one. It is an oak measuring eight feet in girth 

 and is placed in the broken-down remains of a hedgerow. 

 20 



