Leading Foresters. 95 



value of stands. His "Forest Mathematics" (1835) 

 in ■which he introduces factors of form and many other 

 new ideas was an original contribution to science. 



Very different in character from these four leaders 

 was the aggressive, sharp-witted Friedrich Wilhelm Leo- 

 pold Pfeil (1783-1859), who, without a university edu- 

 cation, and ia spite of his poor knowledge of mathe- 

 matics and natural history, advanced himself by native 

 wit and genius. After a brief period of eniiployment in 

 private service, in the province of Silesia, he accepted 

 the position of professor of forestry at the Berlin Uni- 

 versity in 1821 in connection with Hartig, with whom, 

 however, he was at sword's point. It was at his insti- 

 gation, with the assistance of von Humboldt, that the 

 school was transferred, in 1830, to Eberswalde, Pfeil be- 

 coming its director. 



, WhUe Hartig was a generalizer, Pfeil was an indi- 

 vidualizer, free from dogma and most suggestive ; a free 

 lance and a fighter. Critical in the extreme and prolific 

 in his literary work, he domineered the forestry literature 

 of the day by means of his Kritische Blaetter, a journal 

 of much import and merit. K«.v\ 



The youngest of the group, Onstav- Heyer (1799- 

 1856), a thoroughly educated man, combined the pro- 

 fessorial position in the University of Giessen (1835) 

 with practical management of a forest district, but in 

 1843 abandoned the latter in order to devote himself en- 

 tirely to literary work. He was one of the clearest and 

 most sytematic expoimders, and both his Waldbau (silvi- 

 culture, 1854) and his Waldertragsregelung (forest or- 

 ganization, 1841) are classics. He devised one of the 

 most rational methods of forest organization, and, im- 



