AUGUST, 1911.] 



101 



Saps and Exudations. 



by one man. This may seem impossible 

 or difficult, but many agree that tapping 

 operations of the future will be con- 

 ducted with the aid of steam, electric, 

 or other power. Experiments in Tobago 

 show that eight to ten-year-old trees 

 tapped with mallet and chisel will give 

 an average annual return of 3 to 4 oz. of 

 dry rubber per tree. A few trees give 

 1 to li lb. On one plantation it is 

 recorded that some years ago a few 

 hundred ten-year-old trees gave | to 

 | lb. per tree. 



In 1905, experimental tapping with 

 V-shaped cut on a few thirteen-year- 

 old trees in the St. Lucia Botanic Gar- 

 dens, resulted in an average return of 

 11"16 oz, per tree. This yield is similar 

 to that obtained the same year in the 

 vicinity of Bluefields, Nicaragua, where 

 6,000 trees gave an average of 11 3 oz. 

 dry rubber per tree. Results in Ceylon 

 appear to be less favourable, as, accord- 

 ing to the published minutes of the 

 Experimental Station Committee, a tree 

 at Peradeniya. tapped to a height of 

 about 18 ft., gave only 50'90 grammes of 

 dry rubber, although the method of 

 tapping was the full herring-bone on 

 each side, inflicted with mallet and 

 chisel. 



Reports from Mexico show the yields 

 in that country vary from 3 to 12 oz,, 

 according to the age of the trees. The 

 tapping method in most general use is 

 the long V-shaped cut ; but as the apex 

 of the V does not heal well, this system 

 of tapping leaves much to be desired, 

 and is being discarded by the more 

 advanced Mexican rubber planters. Dr. 

 Olsson-Seffer, who has made an exhaust- 

 ive study of the Castilloa tree, recom- 

 mends the half -her ring bone system of 

 tapping, which consists of a longitudinal 

 channel into which oblique cuts lead 

 from one side only, and so, whilst the 

 full area to be tapped is covered, the 

 tree suffers less than by the V cuts. 



NEW USES FOR RUBBER. 



Constantly being Devised— Addi- 

 tional Uses through Recent Dis- 

 coveries BESIDES THOSE FORMERLY 



Published. 



(Prom the Manila Bulletin, June 7, 1911.) 



Only recently the Bulletin gave an 

 article on some of the new uses for 

 rubber, and the fact that with the pre- 

 sent production it would be impossible 

 to overstock the market as the demand 

 was rapidly increasing, in fact keeping 

 ahead of the supply. 



Some additional uses for rubber are 

 here given, new uses being constantly 

 devised, which must result in increasing 

 to some extent its consumption. Some 

 of the more recent new uses are suffi- 

 ciently unique to be interesting and 

 afford an insight into the diversified 

 utility of this remarkable material. 



The following on the new uses and 

 recent discoveries is taken from The 

 India Rubber World :— 



One of the most remarkable, and at 

 the same time, one of the most beneficent 

 uses suggested for rubber, is for the 

 construction of artificial or supplement- 

 ary muscles for children suffering o*- 

 threatened with inf antile paralysis. By 

 the local application of strips of elastic 

 rubber over the weakened muscles, in a 

 manner devised and described by Dr. 

 Roland O. Meisenbach. Buffalo, N. Y., 

 the tensile strength the muscle lacks is 

 supplied, a local stimulus effected and 

 contractions prevented, while the appli- 

 cation being painless and not incon- 

 venient, and the effect being continuous 

 and independent of the patient's volition, 

 the remedy is especially applicable for 

 children. 



Carpet sweepers are equipped by a 

 manufacturer with corner buffers, by 

 means of which the furniture is protected 

 from injury, and they can be applied to 

 either new or old sweepers. Another 

 manufacturer employs rubber in the 

 manufacture of a pad that protects table 

 tops from defacement by hot dishes. 



In the future development of the 

 flying machine, rubber seems destined 

 to prove an important factor. Rub- 

 berized fabric for planes has been 

 given the preference by the most 

 successful practical aviators, while the 

 extent to which a safe and successful 

 landing depends on the quality of the 

 rubber tyres with which the " plane " is 

 equipped, has induced leading tyre 

 manufacturers to bestow particular 

 attention on the production of "aero- 

 plane tyres." 



In the form of hose, rubber comes into 

 use in an ingenious machine, employed 

 by paviors in Germany, for ramming or 

 tamping paving blocks into place. The 

 pneumatic ramming tool is connected 

 by rubber hose with a portable air com- 

 pressing plant, and the compressed air, 

 acting on its mechanism, causes it to 

 deliver a rapid series of hard blows on 

 the paving stones that are being set. 



Another use to which rubber hose is 

 put is in the operation of an ingenious 

 vacuum cleaner, for which a stream of 

 water from an ordinary faucet furnishes 

 the power. Passing down one arm of a 



