From the text ... ' It is almost impossible for forestry to do anything in defense against smoke devastation. Even when conditions of terrain permit, the cultivation of timber with higher smoke resistance is outweighed by the important factor of mininum mass effect. Incidentally, deciduous woods are the only ones one should consider for extablishing smoke resistant timber in appropriate terrain conditions. Where the latter do not exist, there remains only as a preventative measure, the transition from forest to field or meadow. Alternatively, mixing of all useful deciduous woods in a planter or middle forest operation is indicated. In case all other management plans fail the scrub forest with a short turnover cycle, is advisable, since it protects young growth and insures soil freshness. As far as possible, beech and oak trees should be scattered throughout the stand in order to spread the benefit of soil improvement to the whole stand. Maximum ease of management is accomplished by creating mixed groves. Great value should be given to the use of pines as fill-in, protective, or production timber. Conversely, cultivation of deciduous tree shields and of screening hedges rarely achieves the desirable result, since they lose their leaves in winter and thus provide little protection.'