GROUND-WOOD PULP. 



59 



15). In this series the Jordan in every ease brushed as close as, or 

 closer than, when the regular mill stock was being used. 



The ground wood from Alpine fir and Engclmann spruce gave the 

 best results from the standpoint of operation on the paper machine. 

 All of the sheets in this series exhibited very good strength, while the 

 color of those from Alpine fir, amabilis fir, and Engelmann spruce 

 compared favorably with that of the spruce standard. So far as the 

 paper-making qualities of the pulps are concerned, the 17 tests demon- 

 strate that all of the woods used are satisfactory for news-print paper. 

 It was suggested by the men operating the paper machines that even 

 more satisfactory results could have been secured had a lighter sheet 

 been run, such as is used for catalogues. Table 58 summarizes the re- 

 sults of strength and color tests on the papers manufactured from the 

 commercial pulp samples. If the results of the single trial to obtain a 

 good color for each experimental sheet are compared with the color 

 ratings given in Table 3 for a few actual trade news-print sheets, it 

 will be seen that the latter vary almost as widely in color as the 

 experimental papers. 



Table 3. — Color ratings of commercial news-print sheets. 



J Red. 



Green. 



Blue. 



Black. 





Red. 



Green. 



Blue. 



Black. 



A 



' 61 



.-. 61 



66 



1 61 



1 69 



70 



i 61 



69 



1 60 



65 



59 

 67 

 62 

 59 

 65 

 66 

 59 

 61 

 54 

 59 



54 

 50 

 59 

 54 

 60 

 54 

 54 

 59 

 54 

 59 



126 

 132 

 112 

 126 

 106 

 110 

 126 

 111 

 132 

 116 



K 



66 

 68 

 71 

 58 

 65 

 56 

 61 

 69 

 64 



61 

 60 



61 

 56 

 58 

 55 

 59 

 57 

 54 



59 

 58 

 59 

 56 

 57 

 55 

 58 

 57 

 54 



114 



B 



L.... 



114 



c 



M 



109 



D 



N 



130 



E 







120 



F 



P 



134 



G 



H 



Q 



R 



122 

 117 



I 



S 



120 



J 







TESTS ON NEWSPAPER PRESSES. 



The final test of news-print paper is, of course, its behavior on the 

 presses and the way it takes ink. Defects which are not apparent 

 when the material is run over the machine become very evident 

 when the paper is run through a high-speed press. Under such 

 conditions, holes, calender cuts, and the like cause the paper to 

 break. 



The first 12 experimental papers were tested on the presses of the 

 St. Louis Republic, St. Louis, Mo. They were run on two duplicate 

 machines of the Hoe sextuple rotary type. Some of the rolls of 

 experimental paper were 67 inches wide, others were 50J inches, and 

 still others 33 J inches wide. One entire city edition and a portion 

 of another were printed on the experimental papers. 



On one press the papers were run at the rate of 369 copies per 

 minute, and on the other at the rate of 372 per minute, or 22,150 and 

 22,300 copies per hour, respectively. This corresponds to a speed of 

 paper through the press of approximately 760 feet per minute. 



