1919 
572 Philippine Journal of Science 
Table II. — Twist of the ropes tested and the relationship of girth to 
* twist — Continued. 
ROPES MADE OF MISCELLANEOUS FIBERS. 
Fiber. 
Girth. 
Length 
of 
twist. 
Twist-4- 
girth. 
mm. 
mm. 
Musa textilis; grrade *‘F” fiber » 
31 
30 
0.97 
Do 
16 
13 
0.87 : 
Musa textilis: crrade “G” fiber* 
26 
25 
0. 96 
Do 
16 
15 
0. 94 
Commercial unclassified fiber _ . . 
45 
45 
1.00 
Do _ 
24 
25 
1.04 
Agave cantata; maguey Cebu No. 2» 
26 
21.6 
0.83 
Agave cantata; maguey from Santo Domingo, Ilocos Sur , 
23 
17 
0.74 
cantaia; maguey from Sulvec. IIocos Sur 
25 
21 
0.84 
Cocos nucifera; salt-water retted, from Caoayan, Ilocos Sur 
50 
38 
0. 76 
Cocos nucifera; machine cleaned, from Laguna husks . 
44 
37 
0. 84 
Do 
24 
20 
0. 83 
Cory pha data: \Qsd - - - 
47 
40 
0. 85 
Corypha data; vascular fiber from petioles; buntal 
22 
20 
0. 91 
Amomum sp __ 
20 
18 
0.90 
Anamirta coccxUus; entire stem of vine twisted into a three-strand 
rope . 
44 
40 
0.91 
DendrocaXamus merrillian'us^ .. 
46 
31 
0.67 
Averacre _ _ . _ ^ _ _ . 
0.87 
_ — __ 
1 
® Machine-made rope ; all other ropes are handmade. 
*' Two-strand rope ; all other ropes have three strands. 
resistant rope test specimens. This machine is of the lever 
type in which the test piece is held in a vertical position. The 
beam is graduated in 1,000- and the dial in 5-pound intervals. 
For testing the smaller ropes, a Riehle testing machine of the 
helical spring-scale type was used. This machine is hand ope- 
rated, by means of a flywheel having a crank, and has a capa- 
city of 600 pounds. The dial is graduated in 1-pound intervals. 
Tensile-strength tests . — The test specimens were prepared 
with an eye-splice at each end, the eyes having an internal 
diameter of 4.5 centimeters, and the splices having three tucks. 
The clear length of rope between the splices was either 50 or 
100 centimeters, with 3 or 4 centimeters extra for marking. 
Upon this clear length of the test specimen the gauge length 
used for determining the elongation was laid off. Except as 
indicated, five test specimens were broken to give each average 
result. Plate II, fig. 2, represents typical test specimens. 
One series of experiments was conducted upon test pieces 
in an air-dry condition. The results obtained from these spe- 
cimens are designated throughout this paper as dry tests. Table 
