This, of course, would be at once fatal to a side by 

 side continuously advancing exploitation, characteristic 

 generally of the method known as a tire et aire, but the end 

 for which that was enjoined would be gained. 



There rnight at first be greater difficulty in bringing 

 out the produce ; but that might be minimised ; and 

 after one or two revolutions, the side by side progression 

 might be carried out on a more extensive scale in allot- 

 ting the allotments, if attention were given to the matter, 

 varying plots and allotments might be so assimilated as to 

 prepare them for a stricter applicatioii of the method 

 referred to, if this should still be found to be desirable. 



Such, in its general principles, was the innovation intro- 

 duced by Hartig, proposing to treat similar patches, 

 though separated from each other by portions of the wood 

 or forest differing greatly from these, as if they constituted 

 a continuous wood or forest, or as if only separated by 

 bogs, or rocks, or fruitful fields. And the principle once 

 admitted, it was found to be a method of exploitation 

 which would admit of great and important improvements 

 beipg made in the whole system v of forest economy. In 

 his work entitled Instmetion in the Culture of Woods, there is 

 discussed by him at considerable length, the system of 

 d. tire et aire, and the best method of so working the forests 

 as to procure the reproduction of these from self-sown 

 seeds, establishing an equalisation of produce and product, 

 and at the same time a progressive amelioration of the 

 forests, ensuring a more abundant and a more valuable 

 supply, be it of firewood, or be it of timber, according as 

 may be desired. 



The publication of this work by Hartig was the com- 

 mencement of a new era in forest economy in Germany. 

 Hitherto all that had been attempted had been to secure 

 a sustained production of wood, now there was to be com- 

 bined with this the natural production of forests in such a 

 way as to secure the progressive improvement of the 

 forests in place of their continued deterioration. And 



