388 



THE INDIA RUBBER WORLD 



[September i, 1906. 



is the regular duty on manufactured steel. Consciiiantly, 

 when automobiles are brought in fully equipped, the tires 

 are valued in with the rest of the car, thus paying 45 instead 

 of 30 per cent. A complete chassis always includes the 

 tires, the cost ofthe.se being figured in. The importer will 

 sometimes take off the tires and ship them separately, to 

 save IS percent, duty, as well as to prevent accident to the 

 tires in the custom house ; but in most ca.ses this is not 

 done, since the saving in duty is nearly offset by the trouble 

 of separate shipment and remounting on this side. The 

 duty, too, is paid by the buyer, who is generally rich, and 

 probably knows or cares little about the difference in larili 

 rates. 



Thus there are reasons for and against imported tires, and 

 each buyer must judge for himself. Luck often decides 

 whether one will cleave to his first choice or try otlier makes. 

 If one's first set are thoroughly satisfactory, one is justified 

 in sticking to that kind, though tires of the same make often 

 <HtTer. Hard luck and ill handling are often blamed on the 

 tires, and in such cases a man naturally tries other makes, 

 though most tire houses give fair guarantees against flaws. 

 Many of the best home and foreign makes are so nearly 

 alike, that it really doesn't matter which he chooses. 



LITERATURE OF INDIA-RUBBER. 



INSULATING RUBBER CABLES. 



IN connection with an extensive account of the Woolwich 

 works of Siemens Brothers & Co., Limited (I^ondon), 

 important builders of submarine cables as well as makers of 

 other insulated wires, The Electrical Revie-M (London) gives 

 the following description of the method of manufacture of 

 vulcanized rubber wires and cables. 



It embraces the tinning of the copper wires, which are 

 then transferred to the bobbins of the stranding machines. 

 After passing through these, the finished strands are wound 

 on suitable drums for passing on to the India riibber cover- 

 ing machinery. 



Each covering machine is capable of dealing with i to 12 

 wires at a time, according to the size of the strand to be 

 covered. In the case of the ordinary vulcanized rubl)er 

 cables, a number of wires with a continuous strip of pure 

 rubber above, and another below them, pass between a pair 

 of grooved rollers, by the action of which the rubber is 

 pressed round each wire. In order to remove the seams left 

 between the continuous wires, the latter are caused to pass 

 over a .separating roller. The wires then entertlie ne.xt sec- 

 tion of the machine, where a layer of white .separation rub- 

 ber is added in a similar manner; a third layer is after- 

 wards superpo.sed, and this constitutes the "jacket" of 

 vulcanized rubber. The wires are then readj- for the tajiing 

 shop. 



From the latter the cable pas.ses to cylindrical vtilcanizers, 

 supplied with steam from the power station boilers. ]'"ach 

 vulcanizer is fitted with two pressure gages, one for the in- 

 ner chamber and the other for the outer jacket, as well as to 

 an instrument which continuously records the ])ressure and 

 time on a paper drum. The vulcanizing history of each coil 

 is thus available for future reference at any time. 



After being vulcanized, the cores are taken to the com- 

 pounding shops ; thcj' arc then measured into coils of stan- 

 dard lengths, tested under water, and stored ready for sale. 



THE PROSPF.CTS OF RUBBER CULTlV.\TION IN CI^'I-ON BY 

 Henry M. Allcyn, planter. Reprinted from The Times of Ceytvn. CoW'nibo: 

 1906. [i2mo. Pp. 2o.j 



A STUDY of the (piestion of yield of rubber, cost of 

 ^~*- production, prices of rubber, and profits. The writer 

 concludes, in the presence of data showing a large > ield in 

 many cases, that an estimate of 2% pounds per tree, at 1 1 

 years, with a later increase, is not excessive. Likewise, 

 that the ])roduction of plantation rubber could not bestoppid 

 witliout keeping prices at a permanent level of under i shil- 

 ling per pound. However, he prefers to leave to his readers 

 the drawing of conclusions, being content to present a com- 

 ])ilation of facts. 



IN CURRENT PERIODlCAtS. 



Gui.s Caoutcliouliferes d' .^mazonie. By O. Labioy. [Report 

 on the rubber yielding niislletoe. ]— yo«;«a/ a" Agriculture 

 Tropicale, Paris. VI-56 (May 31, '06). Pp.131-133. 



Boms el Miuivais Ceards. [Views of MM. DeWildenian and 

 Chevalier on failure of some trees of Manihot Gtaziovii to yield 

 rubber.)— /y«r«<7/ d' Agriculture Tropicale, Paris. VI-56 (May 

 31, '06). rp. 134-136. 



Le Caoutchouc et le Service Agronionique de I'Afrique Occi 

 deiitale I'ranjaise. [Repression of frauds; Caoutchouc schools; 

 superiority of trees to \'\ne&.=Journal d' Agriculture Tropicale, 

 Paris. VI 56 (May 31, '06). Pp. 147-148. 



Versfleichende Zapfersuche nadi Verschiedenen Methoden an 

 Manihol Gtaziovii und k'ickxia elastica in Misalnihe, Togo. By 

 Dr. Gruuer. [Comparative study of different uietho(l.s of rubber 

 tapping, with results attained. ]=/?«')• Tropenpflanzer, Berlin. 

 X f) (June '06). Pp. 382-38S. 



The " Virgen " Rubber of Colombia and its Cultivation in 

 Jamaica. By Robert 'X\\o\\\&o\\.=Journal of the Jamaica Agricul- 

 tural Society, King.stoii. X-5 (May, '06) Pp. 197-199- 



Hxperiinents with Rubber Yielding Plants in Dominica By 

 Joseph Jones, curator botanic station. [Caslilloa elastica and 

 h'untumia elastica] IVest Indian Bulletin, Barbados. \II.i 

 (1906). Pp. 16-20. 



Rubber Kxperiments in St. Lucia. By J C. Moore, agricultural 

 superintendent. [Castilloa elastica. \^=lVest Indian bulletin, Bar- 

 bados. VII-i(i9o6). Pp. 28 29. 



Le Rendement des Kickxia an Cameroun. By E. DeWilde- 

 nian. Bulletin de la Soci^t^ Beige d' Etudes Coloniales, Brussels. 

 XIII6 (June, '06). Pp 381-3S6. 



Die Kautschuk produktion Brasiliens und ilire MutmassMche 

 Zukunst. By Carl Bolle = /?<'/- Tropenpjlanzer, Berlin X-7 

 (July, '06). Pp. 435-445. 



Nocbmals die Kickxiaertrage in Kamerun ■=Der Tropenp/lanzir, 

 Berlin, X-7 (July, '06). Pp. 464-46S. 



Connnenls on Present Underground Cable Practice. I'.y Wallace 

 S. Clark [With reference to the specifications of the Rubber Cov 

 ered Wire ICngiueers' Association ]= Proceedings of the .American 

 Institute of Electrical Engineers, New York. XX\'-4 ( .Xpril, '06). 

 Pp 203-211. 



Une Liane a Caoutchouc a grand Rendement [Review of a re- 

 ))ort by .\u};. Chevalier on Laudolphia Dawee ~\— Journal d'Agn- 

 eulture Tropicale, Paris. VI-58( April, '06). Pp. I12-114 



Exportation et Emballage des graines d' Hevea By L'lyssts 

 B'rnard. Journal d' Agriculture Tropicale. Paris. VI-58 (April, 

 'oh). Pp. 99 loi. 



Thickk is mentioned as an important use of waterproofing 

 compounds the protection of telegraph and telephone poles 

 and fence posts. The waterproofing of concrete floors also 

 calls for considerable material. 



