----
| | | | | |
| | | | | |
31570 | 15.0 | 17.0 | 11.0 | 0.30 | 5 | 3
31571 | 14.0 | 14.0 | 13.0 | .28 | 4 | 4
31572 | 19.0 | 20.0 | 19.0 | .37 | 8 | 6
31573 | 16.5 | 18.0 | 11.0 | .33 | 10 | 8
31574 | 14.5 | 16.0 | 13.0 | .33 | 7 | 6
31575 | 19.5 | 20.0 | 17.0 | .34 | 8 | 5
31576 | 20.0 | 20.0 | 19.0 | .34 | 23 | 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 Nos.
143 and 144 are satisfactory in these respects, the other samples being
more or less thickly specked with shives. The general character and
tests of these papers correspond very closely with No. 1 machine-finish
printing paper, according to the specifications of the United States
Government Printing Office, which call for a sheet not exceeding 0.0035
inch in thickness, strength not less than 12 points, free from
unbleached or ground wood pulp, and ash not over 10 per cent. The
strength factor of such papers is about 0.28. The ash should not be over
10 per cent for this grade of paper, but in spite of the larger amount
used the physical tests are sufficiently high. It is to be noted that
the physical tests of samples Nos. 138 to 142, inclusive, are higher
than in Nos. 143 and 144, in which 23 per cent of soda poplar was used,
which shows clearly that hemp-hurd stock imparts strength and folding
endurance to a greater extent than does soda-poplar stock. From these
preliminary tests it would be concluded, therefore, that hemp-hurd stock
acts similarly to soda-poplar stock, but will produce a somewhat harsher
and stronger sheet and one of higher folding endurance. Undoubtedly,
there is more dirt in the samples than would be tolerated by the trade,
but this was to be expected, since in this preliminary work the raw
material was sieved by hand screens instead of by automatic machines
which would sieve more thoroughly.

=CONCLUSIONS.=

There appears to be little doubt that under the present system of forest
use and consumption the present supply can not withstand the demands
placed upon