576 Philippine Journal of Science 1919 
TABLE IV.—Ropes made of Philippine fibers arranged in order of mean 
tensile strength when wet, etc.—Continued. 
ROPES MADE OF MISCELLANEOUS FIBERS. 
{ Mean wet tensile 
strength. 
Fiber. 
No. we Per sq. | Per sq. 
cm. inch, 
— xe 
} Kilos. Lbs. 
1| Musa textilis; grade ‘‘G’’ abacd; rope, 16 mm. in circumference® --_----- 1,180 | 16,700 
2 | Musa textilis: grade ‘“F’”’ abac4; rope, 31 mm. in cireumference® -------- 946 | 18,500 
3 | Musa textilis; grade “F’’ abac4; rope, 15 mm. in circumference® -_------ 923 | 18,100 
4.| Musa textilis; grade “G’’ abac4; rope, 26 mm. in circumference® ---- ---- 759 | 10,800 
5 | Agave cantala; maguey; grade, Cebu No, 28_..--------------------------- 651 9, 220 
6} amon OP... 55a Soc eae seo cee 325 4, 600 
1 | Coryphaelata; buntal; vascular fibers in petioles ------------------------- 257 8, 650 
8 | Dendrocalamus merrillianus> ___......----------------------------------- 179 2, 540 
9 | Cocos nucifera; rope, 24 mm. in circumference® -..-.--.------------------ 148 2, 100 
10 | Cocos nucifera; rope, 44 mm. in circumference ......-------------------- 146 2,070 
11 | Cocos nucifera; rope, 50 mm. in cireumference® _-_-----.----------------- 186 1, 940 
12' Anamirta coceulus t__.......--.-.------------------ ---------------------- 110 | 1,570 
PF RORES SS SSS igs ois a Goto Ope meet oa en rer nen een yee 480 6, 816 
7 Machine-made rope; all other ropes are handmade. 
> This rope has two strands only; all other ropes have three strands. 
¢ Immersed in stagnant tap water twenty-one days before testing; all other ropes were 
steeped in tap water only twenty-four hours before being tested. Rope made of fiber that 
had been machine cleaned at the Bureau of Science from Laguna husks. 
4 Rope made of fiber that had been machine cleaned at the Bureau of Science from Laguna 
husks, 
* Rope made at Caoayan, Ilocos Sur, from salt-water retted coir. 
* Three-strand rope made of the entire stem of the vine. 
rarely in three; this shows that the various strands are not 
equally taut in manufacture, and that the intensity of stress is 
greater in some fibers than in others. 
As a substitute for stresses calculated on the basis of sectional 
areas of cordage and similar material (paper, leather, etc.), 
the computation of whose solid sectional area presents diffi- 
culties, Reuleaux™* in 1861, and Rankine** in 1866, intro- 
duced the concept of breaking length. The breaking length of 
a rope is that length which when suspended at one end will 
cause the specimen to break of its own weight. It is com- 
puted by dividing the breaking load or tensile strength in 
pounds or kilograms by the weight in pounds per foot or in 
kilograms per meter, respectively, as follows: 
Breaking load 
Weight per unit length 
— Breaking length. 
*Heermann, Paul, Mechanisch- und Physikalisch-technische Textile- 
Untersuchung. Julius Springer, Berlin (1912) 160-161. 
