Periodical Literature. 211 



trained men, organized for this work, can do justice to this class 

 of work. 



Bin Stuck Preussischer Forstgeschichte. Zeitschrift fur Forst-u. Jagd- 

 wesen, February, 1909, pp. 71-104. 



In an address, which Dr. Martin delivered 



Meaning upon assuming the directorship of the For- 



of est Academy at Tharandt, he defined fore- 



Statics. stal statics as "the art of weighing" fore- 



stal operations. 



Lately this subject has been raised to a special course at this 

 and the Prussian academies. Martin accentuates the practical 

 importance of this discipline and points out various statical prob- 

 lems lately discussed; the strictures made in the Bavarian legis- 

 lature regarding the surplus of old age classes (briefed in the last 

 number of the Quarterly) could be answered only on the basis 

 of statical calculations ; the question of profitableness of the com- 

 posite forest is a problem in Alsace-Lorraine ; the long rotations 

 in France and in the pineries of Prussia, and in Saxony the ques- 

 tion of species mixture, manner of reforestation and thinnings, 

 call for statical investigation. 



He refers to Heyer as having laid too much stress on the mathe- 

 matical methods and too little on purely economic considerations. 

 He admits that the foundations of forest management cannot be 

 laid on generally applicable mathematical data, nor can yields 

 and costs and interest rates be determined with precision. Yet, 

 are we, therefore, to give up the calculations which underlie a 

 well-planned management? If we make such undertakings de- 

 pendent upon exact calculations, we could not pursue a colonial 

 policy, could not build railroads and ships or build factories or 

 conclude commercial treaties, because these things too withdraw 

 themselves from exact mathematical demonstration as regards 

 their profitableness. Yet the results of increased cost of produc- 

 tion or of increased or reduced stock can be weighed without pre- 

 cise algebraic formulae. The calculation is only one of the 

 guides, and judgment in the direction of natural history and of 

 economics must supplement the calculation. History and experi- 

 ence in combination with biological, mathematical and economic 

 principles must guide the progress of forestry. 



Although similar bases and ideas underlie forest valuation, in 



