0« the Flax of New Zealand. 343 



After having tried the strength of tuelve lengths of 

 hemp, as above dcscribedj and having divided the sum by 

 that number, to ascertain the mean strength of each, I 

 found that it was equal to 1 6-^-, while that of the fibres of the 

 Phormium fenax, tried m the same state, was 23-^. The 

 filaments of the aloe gave only 7, flax 1 1|-, and silk 34; or, 

 in other words, the fibres of hemp broke only with a weight 

 of 400'3917 grammes, that of the flax of New Zealand by 

 590'5034 grammes, flax by 295-8228 grammes, and silk 

 by 855-9978 grammes. 



The hemp and flax which I employed for these experi- 

 ments were, the first fibres of the best kind produced in the 

 department of L'Orne. I extracted, by maceration and 

 slight friction to detach the parenchyme, the fibres of the 

 aloe from a leaf of the Agave j'ietida, Linn, or the Fiir- 

 cra-a gigariiea, Vent, which was given to me by my col- 

 league C. Thouin. 



I must here observe, that at first I took the filaments of a 

 diameter much smaller, J^jth of a millimetre, or 0-0221 of a 

 line, and even less ; but I soon observed that it was difllicult 

 to obtain them of that tenuity without a great many in- 

 equalities and other defects, which prevented the exactness 

 of the results ; besides, the more delicate they were, the 

 more difticult it was to ascertain their diameter. I paid 

 attention, therefore, to those only the diameter of which 

 was Jj of a millimetre. 



It may, therefore, be readily conceived what advantage 

 it would be to the navy to have ropes, the strength of 

 ivhicli, were it confined merely to this proportion, would! 

 be almost one-half greater than that of hemp ropes. But 

 I have no hesitation to assert that it will far exceed it ; for 

 the fibre* of the flax of New Zealand, according to a series 

 of comparative experiments which I made on purpose to 

 determine the tension of which they are susceptible before 

 they break, are more tensible by one-half than those of 

 liemp ; and the principal cause of the diminution of the 

 strength of a rope, in proportion to its being more twisted, 

 arises in particular from the fibres of which it is composed 

 experiencing diflercnt degrees of tension, the strength 

 and inequality of which are increased by torsion. But it 

 is evident that the more the fibres which enter into a rope, 

 are susceptible of tension, the less is the dillerence in the 

 distribution of their strength, whence it results that the 

 most tensible fibres, ca^tcris parilnis, will always make tli^ 

 best ropes. 



It has been observed that certain kinds of hemp, v ith' 

 Y 4 . stifl; 



