232 



THE INDIA RUBBER WORLD 



[May 



1 90 1. 



the other about % inch, and rolling down with a hand roller 

 to press them firmly together. This is continued until the de- 

 sired length is obtained — usually 12 to 20 feet. 



Another ply is now built up in the same manner, while the 

 scrap pieces are here filled in as well. If these pieces have be- 

 come dried from age, a little quick curing cement applied to 

 the surface will restore the friction and make it stick securely. 

 When the slab has attained the desired thickness, apply to the 

 outsides a layer of duck frictioned on one side only — the side 

 placed next to the packing. 



This packing is usually made in slabs from >8 inch to i inch 

 in thickness, though sometimes it is made even thicker. These 

 slabs are then taken to the vulcanizer and cured, after which 

 they are confined in the hydraulic press to bring the plies firmly 

 and solidly together. The slabs are next placed on a table 

 and cut into strips in the same manner as the pure gum pack- 

 ing. 



Hydraulic packing, which sometimes is called linen packing, 

 is made in exactly the same way as the square duck, but the 

 duck and friction which enter into its composition are entirely 

 different. The duck used here is very strong but light in 

 weight, and to combine these two qualifications leather cloth 

 is most universally used. The friction should be a hard curing 

 compound, which will not burn while being subjected to the 

 excessive heat necessary to produce this packing. After the 

 strips of duck have been cut and the slab made up and vulcan- 

 ized, it is cut into strips and coiled up as in the case of square 

 duck. Now comes an extra process, whereby the packing is 

 made to conform to any degree of hardness, even to flint hard. 

 The coils are taken to a small hydraulic press, where they are 

 subjected to a long curing process at a quite high temperature, 

 until they obtain the degree of hardnessdesired, The reason 

 for cuttmg this packing into strips before this last process is 

 begun will be comprehended when it is explained that it would 

 be almost impossible to cut it after becoming so intensely 

 hardened. 



Next in order is rubber-back packing. This consists of the 

 regular square duck packing with a strip of pure gum packing 

 securely vulcanized on one side of the square section. To make 

 this, stretch a slab of pure gum packing upon a table and with 

 a brush cover the upper surface with several coats of quick cur- 

 ing cement. When this cement becomes perfectly dry the strips 

 of square duck packing are laid side by side on the cemented 

 side of the rubber until the entire surface is covered. After it 

 becomes well set take the slab to the press and confine it be- 

 tween the plates until the cement is cured, after which it is cut 

 into square strips, as with other square packings. 



Last of all comes the rubber core packing. This is not so 

 generally used, yet it is fully as important, and the process of 

 manufacture is most interesting. This packing has a round 

 core of pure gum running through the center of the strip from 

 end to end. The round piece of rubber is run out through a 

 tubing machine and cut oflf in lengths of 12 or 15 feet, or any 

 other length desired in the finished packing. The frictioned 

 duck which makes the outside covering of this packing is pre- 

 pared in the same manner as for other duck packing. It is also 

 pieced together from bias sections and then cut into strips of 

 sufficient width to make the correct diameter when rolled 

 around the rubber center. 



The rubber core is first well covered with cement and the 

 edge of the strip of duck placed securely along the cord. The 

 cord is now laid between the two bottom rolls of a three roll 

 wrapping machine, after which the top roll is lowered securely 

 against the cord. 



While the rolls are turning the cord around, some tension 



should be placed on the duck to cause it to roll up tightly and 

 evenly around the cord. These round strips are now wrapped 

 with wet muslin cloth and consigned to the vulcanizer to be 

 cured. This done the cloth is removed and the packing coiled 

 and tied up for shipment. 



This review gives a general idea of most of the kinds of rub- 

 ber and duck packings now on the market. It is safe to pre- 

 dict, however, that with American genius at work, and in view 

 of the continual experimenting and research, it will not be long 

 before there will be new inventions, new discoveries, and per- 

 haps new packings that will entirely eclipse any that are now 

 in use. 



UNPROFITABLE CAB SERVICES. 



THE electric vehicle companies that started out with such 

 a flourish a year or two ago seem to be gradually fading 

 away. A circular sent to stockholders of the New England 

 Electric Vehicle Transportation Co., organized to operate an 

 electric cab service, makes a showing of assets of $1,982,995. 

 There are said to be outstanding 224,335 shares, on which $10 

 has been paid, but the present price of $3 per share indicates 

 that some of the stockholders expect a considerable shrinkage 

 from these figures of assets. No statement showing any oper- 

 ating profit has yet been made, and the winding up of the 

 company is in prospect. 



The Illinois Electric Vehicle Transportation Co., of Chicago, 

 decided in March to go out of existence — in view of the losses 

 sustained, as the directors expressed it, due to heavy repairs 

 continually made necessary by the bad condition of the streets. 

 The original capital of the company, $25,000,000, was reduced 

 some time ago to $2,500,000. The highest price in public trad- 

 ing in its shares was 16^ ; later as low as lYs. was quoted. It 

 appears that 158,620 shares were issued, on which $793,700 had 

 been paid in. 



These companies, together with similar ones in New York, 

 Philadelphia, and Washington, were organized as sub compa- 

 nies of the Electric Storage Battery Co., through the Electric 

 Vehicle Co., of New York, and capitalized at wildly extrava- 

 gant figures. With the exception of that operating in New 

 York, it is reported that none of the companies has made any 

 money. Their stocks all boomed tremendously at first, but a 

 recent report on their condition showed a shrinkage of $58,- 

 000,000 in market value from the highest. Electric Vehicle 

 (New York), preferred, at one time reached 150; on a recent 

 sale of 100 shares 27^2 was quoted. 



It has looked very much to an outsider as if promoters' 

 profits, rather than the introduction of automobiles, were 

 aimed at. At any rate the lack of financial success of these 

 undertakings, together with the withdrawal of cab services 

 once started, will have anything but a favorable effect upon 

 the growth of automobilism. 



RUBBER INDUSTRY IN SWITZERLAND. 



A REPORT on the rubber industry in Switzerland refers to 

 the world's consumption of shoe elastics having become 

 smaller, and says that the tendency of the demand is for 

 thinner threads. Wherever elastic goods have been required 

 for export in large quantities, the cheaper kinds have been de- 

 manded. The total export was increased somewhat last year, 

 however, on account of increased orders from Spain. Not only 

 was the continued high cost of rubber detrimental to the in- 

 dustry, but the cost of yarns increased, cotton in some cases as 

 high as 50 per cent, and woolen in some cases joo per cent. 



