September 1, 1912.] 



THE INDIA RUBBER WORLD 



573 



18,000 or more inhabitants have sent out' to the world, sugar, 

 cocoa, coffee, cocoanuts, nutmegs and rubber. 



Tobago has the distinction of being the birthplace of, not only 

 a most excellent system of tapping Castilloa trees, but an equally 

 good system of coagulation. 



It will be remembered that almost all tappers of plantation 

 Castilloa were in the habit of gouging the bark much after the 

 fashion of Hevea tapping, either in zig-zags, half-herring bone, or 

 adaptations of those systems. As the bark is exceedingly tough, 

 a very strong knife was necessary and very definite channels 

 were cut. Tobago, however, turned its back upon established 

 procedure, and instead of cutting the bark away, simply pierced 

 it with a broad chisel — getting just as much latex, and allowing 

 the wound to heal very quickly. Then, instead of coagulating 

 with alum or amole, Mr. Harry S. Smith, a planter there, con- 

 structed a centrifugal machine, which promptly and thoroughly 

 coagulated latex. This machine was different from the ordinary 

 centrifugal used in the coagulation of rubber; for example, it 

 had certain valves which admitted of the escape of the "black 

 water" while the machine was running at full speed. It also 

 coagulated the rubber in something like 20 minutes, leaving only 

 about one per cent, of water in the rubber. Taken by and large, 

 the machine was wholly novel and thoroughly successful and 

 Tobago — through Harry Smith — scored a second time. 



Castilloa trees in Tobago seem to be excellent producers, and 

 the planters there are tremendously interested in this tree. They 

 believe in high tapping — often going 10, 20, 30 and even 40 feet 

 up on the tree. At the present time, however, they are tapping 

 about 20 feet up, using light bamboo ladders for that purpose. 



The first chisels were made from ordinary kitchen knives with 

 the blade broken off and sharpened at both sides and at the flat 

 base. This gave a cleaner cut than the chisel would, and was in 

 itself really a new type of tapping tool. The tapping knife is 



the tree is tapped at a time — sometimes only one-third. To 

 prevent the collection of too much scrap in the wounds, the bark 



T\velve-Ye.\r-Old Hcvea, Experiment Station, St. Clair. 



is wiped off with a wet brush which is continually dipped in a 

 can of water. Mr. CoUens gives the following results of his 

 Castilloa tapping on a typical estate in Tobago : 



RESULTS OF TAPPING CaStiUoO, LURE ESTATE, TOBAGO. 



First tapping from April 6 to May 18. (Trees Fruiting.) 



Average 



Castilloa Trees, Tobago. 



struck with a wooden mallet until fh'e bark is 'penetrated — the 

 latex dropping down into an oilcloth apron which is fastened 

 around the base of the tree. About one-half of the bark area of 



