Periodical Literature. 277 



We call attention to the work of Dr. Judson F. Clark in this 

 direction on the Balsam Fir as reported in F. Q. vol. I, p. 6-1 1. 



Das Gesets dcs Inhalts der Baum stdmme etc. Forstwissen schaftliches 

 Centralblatt. Aug., 1912. Pp. 397-419- 



Still another caliper is now to be had, the 

 Precision main aim of which is accuracy. It is con- 



Calipers. structed by Mr. Philip Flury, Assistant in 



the Swiss Experiment Station, and is de- 

 signed to combine easy manipulation and easy reading, with solid 

 construction, greatest amount of lightness and highest accuracy. 

 It can be had in sizes of 35, 60, 80 and 100 cm., from Pfenninger 

 Co., Zurich. Its high price, however ($12.80 for a 30 inch cali- 

 per) will prevent its very general use except in scientific investi- 

 gations. 



The rule is of wood, with brass linings; the scale is read from 

 an inclined celluloid plate with a definite index and various de- 

 vices for distinct reading. The moveable arm is made of alum- 

 inum in a single piece, which avoids temperature and moisture in- 

 fluences; the handles of the anus are covered with leather, to 

 protect against cold- To insure parallelism, only two points of 

 the guide diagonally placed touch the rule, while a spring is in- 

 serted on a third (interior) point to prevent slack movement, and 

 and adjusting screw working on a metal plate over a strong 

 spring permits exact setting of the arm. Such a caliper was kept 

 two hours in water and then exposed for an afternoon to rain: 

 the slight change in volume which followed could be easily 

 eliminated by the adjusting screw. 



Bine iicuc Mcssklufipe. Schweizerische Zeitschrift fiir Forstwesen, 

 March, 1913. Pp. 89-91. 



UTILIZATION, MARKET AND TECHNOLOGY. 



^ . Dr. Schwalbe in a comprehensive address 



points out that the chemistry of wood is 

 still poorly understood, and hence all in- 

 dustries which work chemically with wood, 

 i. e. by means of changes or decomposition 

 of wood substances are handicapped. This is due to the fact that 

 the materials, under which the collective name of lignin form 



