GROUND-WOOD PULP. ; 51 
EXPERIMENTAL MANUFACTURE OF PAPER. | 
A limited amount of paper (waterleaf) was made experimentally 
at the Madison laboratory from the various pulps and tested for 
strength and color. In every case the conditions of manufacture 
were identical, and no coloring matter was added to any of the pulps 
: in the beater. The paper machine used was too small to permit of 
i. Fig. 39.—Engelmann spruce (Picea engelmanni). 
‘TYeliable data being obtained upon such points as operation of the 
_ pulp on the machine, calendering, and the like. 
% In the matter of color the various wood fibers (unsteamed) may 
_ be arranged in the order given below, the basis being the number of 
parts of black which each sample contained, that with the smallest 
number ranking first. It should be remembered that the arrange- 
Ment is made as the result of tests on many different samples of 
_ paper from the same wood, rather than on the particular samples 
