xm, A. 6 King: Philippine Coir and Coir Cordage 293 



Tables I and II show the diversity of the filaments in cross 

 section. They vary from specimens w^ith fine circular sections 

 having a diameter of 0.152 millimeter to those with very coarse 

 elliptical sections having a width of 0.939 millimeter and a thick- 

 ness of 0.482 millimeter. Between these two extreme types are 

 filaments having a variety of irregular cross sections. In fact, 

 it is not uncommon to find differently shaped cross sections at 

 various points in the same filament. Fine and medium filaments 

 tend to have a circular section whereas the coarse ones, and par- 

 ticularly those that are very coarse, are invariably elliptical. 

 Most of the filaments of the two samples tested are slightly 

 tapered, as is clearly shovm in Tables I and II. For the sake 

 of simplicity in calculation the cross-sectional areas of the single 

 filaments at the point of rupture were considered to be either 

 perfectly elliptical or perfectly circular. For all general pur- 

 poses the diff'erence between the true area and the calculated 

 area is so small as to be insignificant. It will be seen that 

 most of the filaments are characterized by two principal cross- 

 sectional dimensions: (1) a maximum diameter and (2) a min- 

 imum diameter, which have been designated width and thickness, 

 respectively, in Tables I and II. 



PHYSICAL PROPERTIES OF COIR FILAMENTS IN TENSION 



Description of testing apparatus used. — For determining the 

 tensile strength, tensile elasticity, elongation, and permanent set 

 of single coir filaments, I devised a simple but accurate ap- 

 paratus. A sketch of the mechanism with a filament clamped 

 in place is shown in fig. 1. It consists of two paper-lined grips, 

 /-J\ for clamping the filament ; a rigid stand, S, for supporting 

 the gripping elements; a cardboard scale. A, graduated in milli- 

 meters for determining the elongation of the test specimen ; and 

 a device, H, K, V, T, for applying the load at a constant rate 

 and cutting it off at the desired instant. From the lower grip, 

 .7\ is hung a pan, P, for receiving the small lead shot with which 

 the hopper, H, is filled and which flows through the spout, K, 

 when the valve, V, is opened. The device for applying the load 

 at a constant rate is an auxiliary shot-feeding reservoir used 

 in connection with a Michaelis cement-briquet testing machine. 

 It consists essentially of a smooth sheet-metal hopper, H, sup- 

 ported on a tripod, R, the bottom of the hopper terminating in 

 a spout, K, which is closed by an adjustable valve, V. A trigger, 

 T, located at the base of the tripod, automatically holds the valve 

 open and shuts off the flow of shot at the instant of rupture when 



