PROTECTION AGAINST FOREST FIRES. 235 



from mischief or out of revenge is comparatively slight compared 

 with the number occurring in India, yet they are much more 

 numerous than they should be. 1 



118. Factors determining the Extent of the Injury. 



The danger of fires taking place, and the greater or less extent 

 of area over which they can spread, are not anything like the 

 same in all localities, but are always influenced more or less by 

 local circumstances. 



Apart from climatic considerations, the principal factor is of 

 course the nature of the soil and situation, for on these are 

 dependent, to a greater or less degree, the nature of the soil- 

 covering, and the species of tree or trees forming the timber 

 crops. Inferior qualities of soil, with their dry covering of 

 heather and coarse grasses, and such deficiency in soil-moisture 

 that the scrubby growth soon becomes dried up and tinder-like in 

 summer, are much more threatened with danger from fire than 

 fresh soils with strong growth of succulent grass and herbage. 

 And, as a rule, the areas with only inferior qualities of soil are 

 mainly given up to the cultivation of conifers, whilst, unfor- 

 tunately, these resinous species are of themselves much more 

 exposed to danger than the broad-leaved species, more especially 

 as regards conflagrations of the canopy of foliage, from which the 

 latter are only likely to suffer exceptionally during the thicket 

 stage of growth, when dead foliage is still hanging on the twigs. 



The class of woodlands most exposed to danger from fire are 

 heathery stretches covered with pure Scots Pine, where the soil 

 and its covering are not only usually dry, but the timber crop is 

 also, per se, cf an inflammable nature when once fire has broken 

 out. 



Young falls of seedling growth are most apt to suffer from 

 ground-fires when the soil is littered with dry, parched-up weeds, 



1 The Bavarian statistics already referred to state that the investigations held con- 

 cerning the 509 cases of forest fires proved them to have originated as follows : 



Proved. Supposed. 

 From lightning, . . 4 



,, railway engines, 

 ,, negligence, . 

 ,, incendiarism, . 

 unknown causes, 



7 



47 327 



9 64 



50 



