ZACATON AS A PAPER-MAKING MATERIAL. 
21 
experimentally on a small scale, and doubtless in many cases this 
attitude is justified. Experimentation on a small scale has its own 
valuable sphere of usefulness, but great care should be exercised in 
its commercial interpretation. Therefore, with a view to giving this 
material a more reliable or commercial paper value the work was 
continued on a larger scale, more nearly under mill conditions and 
at a place where the services of actual mill emploj^ees could be 
secured for the work. 
The digester employed for this work was of the upright stationary 
type, measuring about 2 feet in diameter by 10 feet high and heated 
by direct steam. The cooked charge was "blown" in the regular 
manner into a blow pit of ordinary construction, where it was drained 
and washed free from black liquor. After screening in the regular 
manner the stock was bleached with mill bleach liquor in a beating 
engine and bleach chest, washed free from bleach residues, made into 
the desired furnish, and suitably beaten, after which it was run 
through a Jordan refiner and then to a Fourdrinier paper machine. 
The greater part of this whole work was performed by the regular 
mill employees. 1 
The material used for the .four cooks of this test was dry, but had 
previously molded to some extent, being the same as that used in 
cooks Nos. 4, 5, and 6. Table V shows the cooking conditions and 
the yields of the four cooks. 
Table V. — Conditions of cooking and total yields of fiber of four cooks of zacaton grass. 
Cook. 
Charge, 
bone dry. 
Caustic 
soda 
added. 
Concen- 
tration of 
caustic 
soda. 
Cooking 
pressure. 
Hours 
under 
pressure. 
Yield, 
bone drv, 
of total 
fiber. 
No. 7.. 
Pounds. 
175 
182 
192 
186 
Per cent. 
20 
19 
18 
16 
41 
90 
Pounds. 
100 
90 
90 
90 
5 
6 
5 
6 
38.6 
33.4 
44.6 
45.2 
No. 8 
No. 10 o 
a The charge in the digester was covered with water and heated to a steam pressure of 50 pounds per 
square inch for 1 hour, after which the water extract was all drained off and the residue cooked in the regu- 
lar manner. 
The higher yield of total fiber in cooks Nos. 9 and 10 is due to the 
lower percentage of soda added and the fact that its concentration was 
lowered by the water remaining in the grass after extraction. The 
general appearance of the pulp of these four cooks was very similar; 
they were soft feeling, bulky, and had a very silky luster. Screening 
was done on a No. 10 cut screen, and in place of a pulp thickener the 
screened stock was run over the wet end of a Fourdrinier paper 
machine and taken off at the first press. This procedure left the 
stock in fine condition to be transferred to the bleach beater. 
iMuch assistance and information was furnished by S. D. Warren & Co., Cumberland Mills, Me. 
