306 



TIMBEE 



made on the hornbeam by M. Julius Marchet in 1895 the 

 weight necessary to crush cubes of the wood containing 

 only 7 to 9 per cent, of moisture was from 2'1 to 2'3 

 times as much as was required to crush cubes of the 

 same saturated with water. 1 



A most interesting series of tests has been recently 

 carried out by Mr. H. D. Tiemann, M.E., M.F., of the 

 Forestry Service, United States Department of Agriculture, 

 given in detail in Bulletin No. 70, showing the effect of 

 seasoning on the strength of wood, and gives more con- 

 vincing proof than anything hitherto of the remarkable 

 and constant increase in the strength of wood caused by 

 drying. The following tables show the degree to which 

 the strength is increased over green timber : 



and for a still drier condition with only 1 per cent, of 

 moisture the increase continued. A completely dry spruce 

 block held up a load four times as great as that which a 

 green block sustained. 



Stiffness, \uthin the elastic limit, was found to follow a 



1 Min. of Proc. Inst. O.E., Vol. CXXIIL, p. 472. 



2 The Spruce referred to in all these tests is the Red Spruce (Piceq, 

 rubens). 



