54 PARA RUBBER, 



Mackenzie's Knife. 

 This consists of a tempered steel head of box section having 

 cutting edges on three sides. The cutting surfaces are in one piece 

 and movable ; by an ingenious screw arrangement the depth of the 

 cutting edges can be adjusted according to requirements by two side 

 guards. The knife can be used for tapping from left to right or right 

 to left. When the incision is so broad that the guard on the upper 

 side of the knife does not rest against the bark on the top side of the 

 cut, the upper guard can be lowered so as to come in contact with 

 the excised area, along which it rubs during paring operations. 



Collet's Knife. 



M. Collet recently exhibited a new tapping knife which I am in- 

 formed has been patented in Belgium. It is made entirely of metal : 

 running down the handle, and coming out at the base, is a bluntly- 

 pointed piece which is inserted in the bark of the tree to be tapped, 

 and by this means the depth of the bark is measured. 



The blade of the knife, which is like a sharp, curved gouge, has on 

 it a brass support, which is set at an angle with the blade and — 

 before cutting— is adjusted at a definite angle, so that when the 

 knife is in use and the brass support resting against the bark, the 

 cut can only go as deep as it is set for, which is the depth of 

 the bark measured at first ; by this means the laticiferous cells are 

 reached, but the cambium is not cut. 



The " Para " Rubber Tapping Knife and Chisel. 

 The two instruments indicated are obtainable from Messrs. Brown 

 & Co., Colombo. The "tapping knife" is designed for making 

 the first incisions in rubber trees, when the paring process is intend- 

 ed to be carried out in the subsequent tapping rounds. It is con- 

 structed to make incisions on the left and right of the perpendicular, 

 and after these cuttings to leave flat surfaces on the lower sides of 

 the incisions ; it provides ample head room for the " Para Chisel " 

 to work in during the early rounds of paring. The " Para Chisel " 

 is a tool for reopening the original incision in such a manner as to 

 renew the flow of latex with the minimum loss of bark tissue. 

 It is first adjusted to cut to the required depth, then placed in the 

 incision and pressed gently forward in a direction parallel to that 

 of the incision. The cutting blade can be easily renewed. The 

 llustration on Plate 8, Series A, shows the construction of the 

 important parts. 



An Implement for Tapping Rubber Trees. 

 The Eastern Produce and Estates Company are responsible for 

 a knife, which has been used on many estates in Ceylon. The 

 patentee claims that it is a simple knife and one which can be eco- 

 nomically used over large acreages of rubber. It consists of a wood- 

 en handle of suitable size and shape, furnished at one end with a 

 stabbing or piercing point for the purpose of clearing the old cuts 



