xin. A. 6 King: Philippine Coir and Coir Cordage 



323 



Fig. 4 shows actual profiles of transverse sections of the 50- 

 millimeter coir rope taken at nine different places, at intervals 

 of 2 centimeters. The diameter of a rope is equal to the diam- 

 eter of the circular opening through which the specimen will 

 just pass and, theoretically at least, forms the basis of other 

 cross-sectional dimensions. Although the circumscribing cir- 

 cumference is the true circumference of the rope and its diam- 

 eter that of the specimen, the position taken by the paper 

 strip used for measuring the girth of the rope represented by 

 line b, is an approximation of the true circumference. To obtain 

 the girth is an easy matter, whereas to obtain the true circum- 

 ference, especially with unskilled labor, involves greater un- 



FiG. 4. Sectional profiles of 60-niiUiineter coir ropes. Actual size. 



certainties and requires numerous circular gauges with graded 

 apertures. Therefore, the diameters given in Tables XI, XII, 

 XIII, and XIV have been calculated by assigning the length of 

 the line b-b (the actual girth) to' a circumference, and the diam- 

 eter of this has been taken as the diameter of the rope. 



Area. — What is meant by the area of the transverse section 

 of a rope is usually very indefinite. Unless information is 

 given as to how it is obtained, this dimension has little signi- 

 ficance, and values based on it are untrustworthy. In fig. 4 

 the sum of the areas representing the strands of a rope is less 

 than the area encompassed by the actual girth, and still less 

 than the area within the circumference. The values approach 

 each other as the size of the rope diminishes and, for small ropes 

 of 50 millimeters girth, the area calculated by assigning the 

 actual girth measurement to a circumference will average 15 



