Periodical Literature. 473 



perhaps halved, so that hardly any financial burden would be ex- 

 perienced. 



Waldbrandversicherung. Forstwissenschaftliches Centralblatt. October, 

 1909. Pp. 418-21. 



In connection with the above the statistics 

 Forest of forest fires in the State forests of Ba- 



Fires varia for the 30 years from 1877 to 1906, 



in just published are of interest. 



Bavaria. On the state forests there were altogether 



2,728 fires covering 2,958 hectar, only two 

 of which ran over areas of more than 250 acres. The total dam- 

 age, including cost of extinguishing fires in the 30 years has been 

 $135,000, hence per annum $4,500, less than $18 per acre of dam- 

 aged area (about 240 acres) less than half a cent per acre of the 

 total forest area (2,300,000 acres). 



The necessity for fire insurance for the Bavarian State forests 

 does therefore not exist. 



That the spring months are the most dangerous, is supported 

 by these statistics, 64% of the cases occurring during March, 

 April, May. Running fires from over 78%, tree fires, hardly 5%. 

 The overwhelming number of cases was due to foolishness or 

 negligence; yet over 15% was due to malevolence. 



Forstwissenschaftliches Centralblatt. October, 1909. Pp. 441-2. 



UTILIZATION, MARKET, AND TECHNOLOGY. 



A very careful, learned and extensive dis- 



Hardness cussion of the factors entering into hard- 



of ness and hardness tests of wood, and of the 



Wood. meaning of hardness, which goes fully into 



the mathematics involved, comes from the 



pen of Dr. Lorenz as a contribution from the Austrian Experiment 



Station. It is of such a character as to make briefing impossible. 



The contents may be seen from the following headings: 1. The 



theoretical equation of the hardness test. 2. The theoretical equa- 



itons of the pressure in hardness tests. 3. The determination of 



the constants of pressure and hardness equations from empiric 



hardness data. 4. The application of theoretical pressure and 



hardness equations to empiric hardness data; subjecting various 



