176 CORDAGE FIBRES 



running across the face at intervals of about 12 inches. 

 The wheel runs in a heavy wooden case and makes 

 about 1 1 o revolutions per minute . The leaf is inserted 

 through a small hole in the case, and held firmly at 

 one end by a strong clamp whilst the rest of the leaf 

 is allowed to whip downwards as the wheel rotates. 

 A heavy block, like the brake of a car-wheel, is brought 

 by means of a lever on to the- leaf and presses it against 

 the revolving wheel. The leaf is thus crushed, and 

 the pulp and epidermal tissue are scraped away by 

 the brass strips and thrown into a pit under the wheel. 

 The fibre is then withdrawn, and the leaf reversed in 

 order that the other end may be cleaned in the same 

 manner. 



In East Africa large, machines worked by power 

 are generally employed which are capable of extracting 

 from one to three tons of fibre per day. An illustrated 

 account of these and other machines has been pub- 

 lished in the Bulletin of the Imperial Institute, Vol. 

 XIII (191 5), pp. 440-442. 



It is essential for the production of good, strong 

 fibre that immediately after leaving the machine it 

 should be well washed with clean water as otherwise 

 both strength and colour are impaired. The factory 

 must therefore be provided with an ample supply of 

 water. Drying is effected by hanging the fibre on 

 lines in the open air, care being taken that it does not 

 become wetted by rain. After drying, the appearance 

 of the product can be greatly improved by the use of a 

 brushing machine to ensure the removal of any par- 

 ticles of dried pulpy matter which may still adhere 

 to it. 



COST OF PRODUCTION 



The cultivation and extraction of Sisal hemp on a 

 remunerative scale require a large amount of capital, 

 as at least 500 acres must be planted to warrant the 

 erection of a factory and the installation of the neces- 

 sary machinery. The crop is therefore unsuitable for 

 individual planters, unless possessed of ample means, 

 but it can be grown with considerable profit by a 

 number of planters working in co-operation. 



