128 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 
invaluable tool of forest management in reliable and suf- 
ficiently detailed form. Even the newest tables are, 
however, still deficient, especially in the direction of de- 
tailed information regarding the division into assort- 
ments. 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and others are now superseded by those of Schwappach 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 R. 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, Karl, 
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 modern text-book which treats fully of all 
modern methods of forest mensuration giving also their 
history is that of Udo Miiller (Lehrbuch der Holzmess- 
kunde, 1899), superseding such other good ones, as those 
of Baur (1860-1882), Kuntze (1873), Schwappach 
(short handbook, last edition 1903). 
