24 BULLETIlSr 404, U. S. DEPAETMEISTT OF AGEICULTUEE. 



Table II. — Comparison between wood and hemp hurds. 





Pulp yield. 



Raw material 



required per 



year. 



Annual 

 growth 

 per acre. 



Acres required for sus- 

 tained supply. 



Material. 



For 25-ton 

 mill. 



For It on 

 of fiber 

 per year. 



Wood 



Two cords 



yield 1 ton of 



fiber. 

 One ton yields 



600 pounds 



of fiber. 



15,000 cords 



25,000 tons 



0.37 cord 

 (about 

 0.55 ton). 



2.5 tons . . . 



40,500 

 10,000 



5.4 



Hemp hurds 



1.33 







The most important point derived from this calculation is in regard 

 to areas required for a sustained supply, which are in the ratio of 4 

 to 1. Every tract of 10,000 acres which is devoted to hemp raising 

 year by year is equivalent to a sustained pulp-producing capacity of 

 40,500 acres of average pulp-wood lands. In other words, in order to 

 secure additional raw material for the production of 25 tons of fiber 

 per day there exists the possibihty of utihzing the agricultural waste 

 already produced on 10,000 acres of hemp lands instead of securing, 

 holding, reforesting, and protecting 40,500 acres of pulp-wood land. 



The annual growth per acre, although decidedly in favor of hurds, 

 has httle bearing on the project, because the utihzation of the hurds 

 is subordinate to the raising of hemp, and the paper manufacturer 

 probably could afford to use only hurds resulting from the hemp 

 industry. 



PHYSICAL TESTS OF THE PAPERS PRODUCED. 



Samples of paper produced in the seven tests were submitted to 

 the Leather and Paper Laboratory of the Bureau of Chemistry. The 

 report of that bureau on its tests is given in Table III. 



Table III. — Report of the Leather and Paper Laboratory of the Bureau of Chemistry on 

 papers manufactured from hemp hurds. 



Labora- 



Run 



No. 



Ash. 



Weight of 500 

 sheets. 



Thick- 

 ness, 

 1/10000. 



Strength (Mullen). 



Strength 

 factor (25 



Folding endur- 

 ance. 



tory No. 



25 by 38. 



25 by 40. 



Aver- 

 age. 



Maxi- 

 mum. 



Mini- 

 mum. 



by 40, 

 500). 



Longi- 

 tudinal. 



Trans- 

 verse. 



31570 



31571 



31572 



31573 



31574 



31575 



31576 



144 

 143 

 142 

 141 

 140 

 139 

 138 



Per ct. 

 13.9 

 14.5 

 9.5 

 10.9 

 11.4 

 13.4 

 10.4 



Pounds. 

 48 

 49 



m 



48 

 42 

 55 

 56 



Pounds. 

 50i 

 51 J 

 52' 

 504 

 44' 

 58 

 59 



33 

 35 

 33 

 38 

 30 

 40 

 40 



15.0 

 14.0 

 19.0 

 16.5 

 14.5 

 19.5 

 20.0 



17.0 

 14.0 

 20.0 

 18.0 

 16.0 

 20.0 

 20.0 



11.0 

 13.0 

 19.0 

 11.0 

 13.0 

 17.0 

 19.0 



0.30 

 .28 

 .37 

 .33 

 .33 

 .34 

 .34 



5 

 4 

 8 



10 

 7 

 8 



23 



3 

 4 

 6 

 8 

 6 

 5 

 15 



There is no system of numerically recording the general appearance 

 and "look through" of a paper, but it can be stated that only papers 



