446 On the Flax of JSTew Zealand . 
The apparatus I employed for ascertaining the strength 
of the different fibres which I subjected to trial consisted 
of two pieces of wood* ten inches in height, fixed on a 
plank in a vertical direction, at the distance of six centi- 
metres, or %.5$8 inches from each other; they were 
slightly rounded at the upper extremity, and on the ex- 
terior part of each was fixed a small iron cylinder, about 
a millimetre in diameter,. To these two small cylinders 
I affixed the filaments the strength of w hich I intended to 
try. They rested on each side on the rounded extremi- 
ties of the pieces of wood already mentioned, I took the 
precaution to employ fibres of the same diameter, that is 
one-tenth of a millimetre or 0 0 143 of a line, which I ve- 
rified by means of a microscope and a good micrometer, 
taking care to twist equally the part of the filament which 
I examined, having chosen it as far as possible of the 
same dimensions throughout its whole length. I tried 
the strength of it from every eight centimetres to eight 
centimetres, or every two inches 11.464 lines, which was 
the distance between the pieces of wood, and I suspend- 
ed from about the middle of it, by means of a wire hook 
well covered with hemp, a weight which I increased un- 
til the filament was broken. 
I took care that it should not be twisted, in order that I 
might ascertain its whole strength, for without this pre- 
caution it would have broken, as is well known, much 
sooner. Besides, for many reasons which it would be 
superfluous to mention here, I should have obtained re- 
sults much less certain ; and it is needless to observe that, 
in such cases, a rigorous determination cannot be obtain- 
ed, but merely an approximation. 
After having tried the strength of twelve lengths of 
hemp, as above described, and having divided the sum 
by that number, to ascertain the mean strength of each, I 
found that it was equal to sixteen and one-third, while 
