752 Forestry Quarterly. 



A very exhaustive article on the subject of 



Durability causes of decay and how to prevent them by 



of Havelik has been running through several 



Railroad numbers of the Centralblatt. In the sum- 



Ties mary, the author states that narrow-ringed 



wood is preferable. The materials used for 



impregnation are divided into two classes : the strong poisons, 



mercury, tar oil and fluor compounds which can keep out even 



MeruUus lacrymans, and the weak poisons, which cannot prevent 



this but other wood destroyers — chlorzinc and coppersalts. The 



latter have the advantage of easier penetration. The strong 



poisons stay more on the surface, excepting tar oil. 



The conductivity of the wood for the impregnation fluid varies 

 from individual to individual tie and from the outside to the 

 inside heartwood, with exception of beech, being incapable of 

 impregnation. Hence, if wood of varying quality is put into the 

 cylinders together, the better woods and therefore more difficult 

 to treat take up less or require more time than the poorer woods. 

 Hence the author proposes to charge cylinders only with woods 

 of the same character of same width of ring and sapwood. Two 

 types of rot are recognized, surface rot and interior rot. The 

 latter deteriorates the railroad ties in the sapwood parts. These 

 therefore must be above all fully saturated. 



Ueber die Dauer der Eisenhahnschwellen. Centralblatt fur das 

 gesammte Forstwesen. March, April, May, 1912. Pp. 



Havelik contributes an important article on 



MeruUus lachryma/ns the question of the distribution of Merulius 



on in nature. For many years the fungus was 



Telegraph Poles considered as domesticated and limited to 



buildings. Toward the end of the 8o's a 

 Telegraph Company in Moravia, Austria, applied to the Forest 

 Management at Mariabrunn for advice regarding the decay of 

 their poles treated with copper sulfate. Dr. Cieslar investigated 

 the question and found that MeruUus lachrymans was the cause 

 of the rapid decay. After giving valuable recommendations the 

 subject was dropped and forgotten until Balasek establishel the 

 frequent occurrence of the fungus on poles in Tabor, Bohemia, in 

 1903. During the past decade Havelik has supervised the man- 



