COLLECTING THE LATEX. 71 



making an initial incision in the bark of the tree before employing the 

 cutting device which is mounted in the other end of the handle a, and 

 consists of a haft or sterna preferably of a curved shape as shown, its cutting 

 end standing at an angle to the haft or stem c. The cutting device proper 

 is of a hollow wedge or triangular shape as shown, the cutting edge being 

 at d and e. 



It has been found that this implement may be placed in the hands of 

 natives and unskilled labourers with much less danger of the trees being 

 damaged or killed than when knives or cutters of other known shapes are 

 employed. 



It is obvious that the above-described implement is also applicable for 

 "tapping" or "bleeding" other trees than those yielding india-rubber. 



The Bowman-Northway tapping knives (Fig. 7) have found 

 favour with a large number of planters in the East 



The following particulars taken from a catalogue published 

 by Messrs Walker & Co. of Colombo thoroughly explain their 

 merits and the manner in which they should be manipulated : 



How to use the Bowman-Northway Patent Rubber Tapping 

 Knives. 



The No. i knife is specially designed to make the first groove 

 when tapping old trees, which have a greater thickness of bark 

 than young trees. It is used much like a plane, the head being 

 suitably adjusted to shave the bark gradually. As soon as the 

 proper depth is reached, the white coloured bark appears, and 

 this becomes lighter and lighter the nearer you get to the 

 cambium, so that by practice it is possible to tell when the right 

 depth has been cut. 



Young trees are more difficult to cut to the correct depth 

 than old ones, as the white bark next to the cambium, mentioned 

 above, is very thin indeed ; it is therefore advisable, under 

 these circumstances, to use the No. 2 knife from the start, and 

 gradually reach the depth necessary by successive parings. 



The No. 2 knife is used for paring the lower edge of the 

 groove originally made with either No. i or No. 2, and when in 

 use should be held so as not to make the cut deeper than the 

 previous ones, which is effected by holding the knife at the 

 proper angle. Leaning the knife over to the right makes the 

 cut deeper, while leaning it over to the left reduces the depth, 

 the object in every case being not to cut deep enough to touch 

 the cambium. The No. 2 knife is provided with a guard or 



