306 
TIMBER 
made on the hornbeam by M. Julius Marchet in 1895 the 
weight necessary to crush cubes of the wood containing 
only 7J to 9J 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.^ 
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 : — 
lu compression parallel to 
grain. 
In bending. 
12 per cent, 
moistnre. 
3J per cent, 
moisture. 
12 per cent, 
moisture. 
Sh per cent, 
moisture. 
Longleaf Pine (pitch 
pine). 
Spruce ^ . 
Chestnut . 
Ked Fir . 
Loblolly Pine Heart- 
wood. 
1- 7 times 
2- 4 „ 
1-8 „ 
1- 7 „ 
2- 0 „ 
2*9 times 
3-7 „ 
2-8 „ 
2- 6 „ 
3- 0 „ 
1'5 times 
1-9 „ 
1-6 „ 
2 '5 times 
2-8 „ 
2-1 „ 
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, ^^ithin the elastic limit, was found to follow a 
' Min. of Proc. Inst. C.E., Vol. CXXIIL, p. 472. 
2 The Spruce referred to in all these tests is the Red Spruce {Picea, 
rubens). 
