DAMAGE CAUSED BY LIGHTNING. 43 



CHAPTER IV. 



DAMAGE CAUSED BY LIGHTNING. 



27. Occurrence and Nature of Damage. 



Lightning, as is well known, strikes trees comparatively fre- 

 quently, either killing them or damaging them to a greater or less 

 degree, although the damage done to woodlands from this cause 

 can hardly be considered important ; and even though there are 

 no practical means at the disposal of the forester to obviate or 

 mitigate the danger, still the matter is of sufficient interest to 

 justify some short notice being taken of it. 



When a tree is struck by lightning, the effects may be extremely 

 various. In many cases it merely destroys a strip of bark about 

 an inch broad, following the direction of the fibres, and hence 

 assuming a spiral course in trees of a tortuous growth. With some 

 broad-leaved species the wound thus inflicted cicatrises, and the trees 

 continue undisturbed in growth, as may often be seen in the case 

 of Oaks, whilst conifers struck by lightning seem invariably to 

 die quickly from the effects. In other cases, the bark of the trees 

 struck by lightning peels off almost entirely, being not infrequently 

 completely smashed, split up, or thrown far around in little 

 splinters. The leaping of lightning from one tree to another is 

 a peculiar phenomenon that may sometimes be noted ; whilst still 

 more remarkable is the manner in which quite a large number of 

 apparently uninjured stems gradually die off in the vicinity of a 

 tree that has been killed by lightning, as may not infrequently 

 be seen in Pine woods. 



Dry stems, or such as are inwardly unsound and rotten, may 

 occasionally be ignited and burned down by flashes of lightning, 

 but in the case of sound green trees this has never been proved to 

 be the actual fact ; under such circumstances, lightning may be 

 the direct cause of a forest fire, although this is seldom the case 

 (see par. 117). 



