GROUND-WOOD PULP. 



35 



tests, except that more wood was employed and more pulp produced. 

 As a rule, 2.5 tons of bone-dry pulp were manufactured during each 

 test, though in some cases 5 tons were made. Data were record ed 

 on power consumption, rate of production, yield, etc., and as soon as 

 practicable the pulp was shipped to mills in the vicinity of Wausau 

 to be made into paper. The aim in making the paper was to produce 

 as good a grade of news print as possible from the experimental pulps 

 under the standard mill practice of the company to which the pulps 

 were sent. The one divergence from this practice was in the treat- 

 ment of the pulp in the beater, as in some cases different amounts 

 and kinds of color had to be added to secure the best results. The 

 amount of size, alum, loading, color, etc., was recorded for each 

 beater of pulp, as also were the amounts of sulphite and ground wood 

 used. The size of screen slots, speed of machine, width of wire, etc., 

 were also recorded. 



The paper produced from the experimental pulps was given a 

 practical try out on the presses of the New York Herald and the 

 St. Louis Republic. The tests were conducted under the ordinary 

 operating conditions of the pressrooms of the two newspapers. The 

 color of the different papers varied considerably, but this was not 

 assumed to detract from their value for news-print purposes within 

 certain limits. Record was made of the amount of waste, the num- 

 ber and causes of breaks, and the number of papers run from a given 

 quantity of material. Observations were also made on the general 

 operating conditions and the appearance of the sheet when printed. 

 Judgment of these latter factors was left very largely to the practical 

 pressmen. 



KINDS OF WOOD TESTED. 



The woods tested to determine 

 pulp were as follows: 



Balsam fir ( Abies balsamea). 



Red fir {Abies magnified). 



White fir (Abies concolor). 



Alpine fir (Abies lasiocarpa). 



Amabilis fir (Abies amabilis). 



Lowland fir (Abies grandis). 



Noble fir (Abies nobilis) . 



Eastern hemlock (Tsuga canadensis). 



Western hemlock (Tsuga heterophylla). 



Tamarack (Larix laricina). 



Western larch (Larix occidentalis) . 



Lodgepole pine, Montana (Pinus mur- 



rayana) . 

 Lodgepole pine, California (Pinus mur- 



rayana). 



' Called "popple" in Wisconsin. 



their suitability for mechanical 



Western yellow pine (Pinus ponderosa). 



Jack pine (Pinus divaricata). 



Loblolly pine (Pinus tseda). 



White pine (Pinus strobus). 



Engelmann spruce, Montana (Picea engel- 



manni). 

 Engelmann spruce, Colorado (Picea engel- 

 ■ manni). 



Sitka spruce (Picea sitchensis). 

 White spruce (Picea canadensis). 

 White birch (Betulapapyrifera). 

 Aspen J (Populus tremuloides). 

 Black gum (Nyssa sylvatica). 



