42 



THE INDIA RUBBER WORLD 



[November i, 1902. 



In this country Balata gum was probably used at about the 

 same time by Mr. W.W.Marks. These wires, being improved 

 in England and America, very rapidly superseded the earlier 

 flexible conductors made by carrying the wires through strips 

 of the textile webbing used in men's suspenders, the wires thus 

 being kept apart from each other. At this period also the de- 

 mand for wire of finer sizes increased. It will thus be seen 

 that by 1880 a great stride had been made from the earlier 

 ideas of interior insulation, and also from those which, in re- 

 gard to exterior work, considered that an iron or steel wire 

 galvanized with a thin coat of zinc was sufficiently insulated. 

 Whereas the earlier metallic insulation was intended to pre- 

 serve the wire itself, the aim of all the later methods has been 

 in addition to prevent the currents of higher pressure and, 

 larger voltage known to the modern electrical arts from escap- 

 ing. The piotection of the wire itself is a small thing compared 

 with the protection which the more perfect methods of manu- 

 facture afTord of life and property. 



From the very first, Mr. Edison, in introducing his incan- 

 descent lamp system two decades ago, insisted that the chief 

 circuits should have their mains underground, and the quan- 

 tity of copper required for such low voltage work produced a 

 condition necessitating such treatment of them. With this be- 

 gan the practice of laying all electric lighting circuits under- 

 ground, a practice which is now universal in the larger cities, 

 and also carried out in many of the smaller ones. Mr. Edison 

 did not, however, manufacture insulated conductors in the or- 

 dinary sense, but ran copper rods through pipes, surrounding 

 the rods with viscous insulating material and also with rope, 

 in such a manner as to keep the sections of different polarity 

 apart, if the two sides of the system were included in one ser- 

 vice conductor. This process, however, has been virtually 

 abandoned in favor of what is known as the "drawing-in " sys- 

 tem, enabling lead covered cables to be inserted at manholes 

 along any given street, and drawn through the ducts of the 

 underground conduits. 



The cables manufactured for such work for telegraphy and 

 telephony, electric light and power, and electric railway service 

 diflfer according to the work which they have to perform, but, 

 broadly, consist of copper wires, single or stranded, sur- 

 rounded by insulated material which is again protected by 

 outer sheathings of lead and iron or steel wire. One notable 

 improvement has been the utilization of paper as a means of 

 insulation; and paper cables are now manufactured in increas- 



ing quantities for all classes of work. The results with these 

 cables may be summed up in the following remark:* 



Experience has shown that paper thoroughly impregnated with insu- 

 lating compound, such as the various tars or resins, forms one of the 

 best insulating materials, provided the paper can be kept reasonably 

 dry, as is insured by the use of the lead sheaths. A very large class of 

 distributing cables are now made with paper insulation, and give the 

 highest satisfaction in actual service. 



It may be incidentally noted that up to the time of the cen- 

 sus report none of the American manufacturers engaged in 

 this industry had produced what are known as deep sea sub- 

 marine cables, these cables being produced exclusively in Eng- 

 land, Germany, and France. A great deal of work, however, 

 answering to this character, for short lengths of sea and for 

 shallower waters, had already been undertaken successfully in 

 this country, and there is no indication from the returns that 

 the heaviest operations of this character could not be safely 

 undertaken. The equipments of the factories, the magnitude 

 of the industry, and the immense range of the product, as dis- 

 closed by the census report, are a full justification of those 

 who believe that America can produce her own submarine 

 cable, if not for international work, at least for service in her 

 OA^n waters and among her own dependencies. 



STATISTICS OF PRODUCTION. 

 In connection with the foregoing report, the census gives 

 the following details of the value of insulated wires and cables 

 manufactured in the United States during the year ended June 

 30, 1900 : 



New York $6,119,878 Indiana $ 330,000 



New Jersey ... 4,701,574 New Hampshire .. . 96,7q3 



Rhode Island 3,912,584 California 65,965 



Pennsylvania 2,696,155 Ohio 15,512 



Connecticut 1.938,075 



Illinois 722,069 Total $21,292,061 



Massachusetts 693,456 



The California production of insulated wire referred to in 

 the above table is supposed to relate to weatherproof wire, from 

 the Pacific Electrical Works, at Los Angeles. The India 

 Rubber World is advised by the census office that the 

 $21,292,061 worth of insulated wire and cable work is entirely dis- 

 tinct from the production credited to the India-rubber industry 

 in the census, although it is known that it covers an import- 

 tant amount of rubber work. 



* Abbott's " Electric Transmission of Energy," 1900. Pp. 185, x86. 



CULTIVATION OF "CASTILLOA ELASTICA" IN JAVA. 



DR. SPIRE contributes to a French journal devoted to 

 tropical planting* a comprehensive report on the 

 planting of Mexican rubber (Castilloa elastica) in the 

 Dutch East Indies, based on personal observations 

 made in the summer of 1901, from which it appears that con- 

 siderable interest in this species exists in that region. He 

 mentio.is, by way of introduction, former reports on the same 

 subject by Dr. P. Van Romburgh, of the botanical garden at 

 Buitenzorg, Java, who has been much interested in watching 

 the development of the Castilloa in that colony, and to which 

 credit is given for some of the details presented here. Dr. 

 Spire is unable, however, after a study of Th. F. Koschny's 

 monograph on the Castilloas, to determine which species has 

 been planted in Java. 



* V Ajfy {culture firati^ut des pays chauds^ Paris. '-6 (May-June, 1902), pp. 

 689-698. 



An interesting fact is that all the Castilloa plantations in 

 Java have resulted from two trees planted as seedlings in 1883 

 by a Mr. Holland, a coffee planter near Buitenzorg. These be- 

 gan to fruit in 1886, and in December of that year 136 plants 

 from seeds yielded by them were placed in the botanic garden 

 at Tjikeumeuh, in an open field, about 10^ feet apart, in two 

 lines forming the letter V. In the third year twelve of these 

 seedlings bore fruit, and in the fourth year the more thrifty of 

 them were 55^^ feet high, and had a girth of 41 inches. In 1901 

 there were 131 of these trees standing, measuring from 50 to 

 65 feet high, and 31 to 53 inches in circumference, breast high. 

 Their crowns form sufficient shade to prevent the growth of 

 weeds, though the ground is spaded up every year. A second 

 planting was made in the garden in March, 1888, when 56 seed- 

 lings were set out 17^ feet apart. A marked difference in the 

 size of these trees is now apparent, those standing near a lane 



