PERIODICAL LITERATURE 1051 



Stockholm-Hallesberg line alone. The width of the danger zone along 

 a railroad varies with ground cover, topography, and exposure to wind. 

 Most of the fires start within 25 meters of the track, but occasionally 

 the distance is as great as 50 meters. The majority of the fires start- 

 ing within 7 to 8 meters of the track originate from material dropped 

 from the ash-pan, while practically all of those starting at a greater 

 distance are the result of sparks from the smokestack. Elaborate 

 fire lines, such as are employed in parts of Germany, are considered 

 impractical in Sweden for economic reasons. One difficulty is in the 

 rocky soil, which can be cultivated or ditched only at great expense. 

 To install the German system of fire lines would involve an estimated 

 initial outlay of 1,452,000 kroner and an annual maintenance cost of 

 200,000 kroner. Since the mean annual damage, as represented by 

 indemnities paid out by railroads, is only 137,000 kroner, the above ex- 

 penditure would not be warranted. An added argument against expen- 

 sive fire lines is the probability that in the near future many of the 

 railroads will be electrically operated. Intensive preventive measures 

 are, however, warranted along limited stretches of railroad traversing 

 forests of unusually high value. The relative merits of various pro- 

 tective measures are discussed. Clean fire lines are usually too expen- 

 sive. While of recognized value, they present the disadvantage of 

 allowing the entrance of wind, which may carry sparks over the cleared 

 space into inflammable material beyond. Close belts of coniferous trees 

 shade out practically all ground cover, but must be kept free of litter. 

 Such belts ofi"er a great advantage over open strips, in that they act as 

 a screen against flying sparks. Of the prevailing types of fences bor- 

 dering the right of way, stone fences or walls are considered most de- 

 sirable, since they act as a barrier against the spread of fire. Wire 

 fences are at least not objectionable, since they are not in themselves a 

 fire menace. Wooden fences, on the other hand, are unqualifiedly con- 

 demned. Hedges are objectionable because inflammable material col- 

 lects underneath them. Preventive measures must extend beyond the 

 right of way. This brings in the question of the responsibility of land- 

 owners. It is proposed to enact laws which require all owners to yield 

 their lands to such protective measures as the authorities adopt. The 

 plan is, in brief, to maintain a dense belt of coniferous trees extending 

 from 30 to 40 meters on either side of the track. Limbs growing near 

 the ground will be removed and, if conditions warrant, all litter and 

 ground cover will be removed. It is anticipated that these strips can 

 be made to yield a revenue not far below that of forests under the 

 usual system of management. The rotation will be short, evidently for 



