138 Germany. 



on yield tables were constructed by many others, but only 

 since the Experiment stations undertook to direct their 

 construction is the hope justified of securing this most 

 inyduable tool of forest management in reliable and suf- 

 ficiently detailed form. Even the newest tables are, 

 however, stiU deficient, especially in the direction of de- 

 taliled information regarding the division into assort- 

 jhents. The yield tables of Baur, Kuntze, Weise, Lorey 

 /and others are now superseded by those of Schwappach 

 for pine and spruce, and of Schuberg for fir. 



As a result of the many yield tables which gradually 

 accumulated, the laws of growth in general became more 

 and more cleared up and finally permitted their formu- 

 lation as undertaken by B. Weber (Forsteinrichtung, 

 1891). 



The idea of using the percentic relations for stating 

 the increment, and of estimating the future growth 

 upon the basis of past performance for single trees was 

 known even to Hartig (1795) and Cotta (1804) who 

 published increment per cent, tables. The methods of 

 making the measurements of increment on standing 

 trees were especially elaborated by Koenig, K!arl, 

 Edward and Gustav Heyer, Schneider, Jaeger, Borg- 

 greve and especially by Pressler (1860) who opened new 

 points of view and increased the means of studying in- 

 crement by causing the construction of the well-known 

 increment borer and in other ways. 



The most modem text-book which treats fully of all 

 modem methods of forest mensuration giving also their 

 history is that of Udo Muller {Lehrbuch der Holzmess- 

 hunde, 1899), superseding such other good ones, as those 

 of Baur (1860-1882), Kuntze (1873), Schwappach 

 (short handbook, last edition 1903). 



