Periodical Literature 53 



published the results in 1897. The instruments have since then 

 been improved, but, outside of Japan and Spain (strange con- 

 trast !), they have not been used. The instrument is constructed 

 similar to self-recording thermometers, etc. As to the practical 

 value of such investigations the author points out that a recogni- 

 tion of the different factors influencing tree-growth must be the 

 basis of silviculture and that these detail studies lead to definite 

 knowledge instead of random opinion. 



The newest improvements consist in an electric connection 

 which permits the observations to be made in the office. * 'Visitors 

 are usually not little astonished to hear that the signal just 

 sounded was given by a tree in the park changing its periphery, 

 so that while I may not hear the grass grow, I can hear the trees 

 grow." 



The cost of the apparatus is about $80. 



Zuwachsautograph. Centralblatt fiir das gesamnite Forstwesen. Nov. 

 1905. PP- 456-461. Ill 



Although real finance calculations in for- 



Forest estry matters are in the United States still 



Finance almost unknown, and even abroad are 



more matters of discussion than of practice, 

 the forest management of governments not being based on 

 financial considerations, and private forestry mostly imitating the 

 practices of the government, it is worth while for us to follow 

 the discussions, if only to secure a better understanding of the 

 nature of the forestry business and of the difficulties, which sur- 

 round the attempt to place it on a true financial basis. In these 

 discussions the expositions by Schiffel are most illuminating, 

 which are the results of a controversy, the gist of which we 

 briefed in Vol. II, p. 186, and Vol. Ill, p. 200, regarding the 

 propriety of applying the soil-rent or forest-rent theory in calcu- 

 lating financial problems. He defines not two but three different 

 principles of finance management, namely, 



1 . A management which tries to secure the highest net annual 

 yield (rent) without reference to the forest capital involved 

 (Waldreinertragswirtschaft — forest net yield management); 



2. A management which tries to secure the highest interest 

 on the soil capital (Bodenrenten — or better rentabilitatslehre — 

 soil- rent management); 



