288 I'he Philippine Journal of Science i9i8 



gives 190 pounds instead of 290 pounds as the strength of Hi- 

 biscus cannabinv^. He says: 



The comparative strength of Coir cordage is well known, but we may, 

 nevertheless, mention, that in some experiments made by Dr. Wight, 

 Coir cordage broke with 224 lb., when Hibiscus cannabiniis bore only 190 

 lb., but the Moorva, [Sanseviera zeylanica] 316 lb. 



The latter form puts coir in a more favorable light and is 

 the way in which Wight's data are quoted by Matthews,^^ Dodge," 

 and Vetillart." All of these authors misspell Wight's name, 

 referring to him as "Wright." 



Spons' Encyclopaedia ^* reduces Wight's results to a single 

 statement: "In Dr. Wight's experiments, coir cordage broke at 

 224 lb." 



Watt " devotes about eleven pages to the discussion of coir 

 cordage, but his only reference to test data is the statement 

 already quoted from 'Spons' Encyclopaedia. Mitchell and Pri- 

 deaux pass over the tensile strength of coir by saying: "Ac- 

 cording to Wright Isicli its strength as compared with hemp 

 is as 224 : 190." 



The bare statement that a particular piece of coir cordage 

 broke at 224 pounds, unaccompanied by additional information 

 as to circumference, diameter, number of strands, or weight 

 per unit length, is of very little use. Owing to their incomplete- 

 ness it is evident that Roxburgh's results as quoted by Royle 

 and others, also have little value for the purpose of comparison 

 with tensile-test data secured by other investigators along similar 

 lines. The changes in form that they have suffered at the hands 

 of certain writers have not increased their usefulness. Royle 

 is the only writer who mentions that Roxburgh's specimens 

 were ruptured by weights suspended from them. Undoubtedly 

 the results were obtained under rather disadvantageous condi- 

 tions, such as difficulty in applying the load uniformly or in 

 adding sufficiently small increments, difficulties that the use of 

 modern testing machines have overcome. The quotations given 

 are typical of the published literature on the physical prop- 

 erties of coir cordage, and show that the data therein presented 

 do not justify the expressed opinions that coir is elastic;^" that 



"Op. cit., 116. 

 " Loc. cit. 

 " Loc. cit. 



"Op. cit., 426-437. 



"Matthews, loc. cit.; Mitchell and Prideaux, loc. cit.; Dodge, loc. cit.; 

 Watt, op. cit.; Vetillart, loc. cit.; Copeland, loc. cit. 



