370 



THE INDIA RUBBER WORLD 



[September i, 1901. 



INSULATION FOR A GREAT POWER PLANT. 



THERE is being constructed at Thirty-ninth street and 

 East river, New York, a power station for the New 

 York Gas and Electric Light, Heat and Power Co., which 

 will have the largest capacity of any plant in the world — 

 even more than the plant at Niagara Falls as that now 

 stands. The New York plant has been developed gradually 

 since 1S96. The cables for the transmission of power are lead 

 covered, three cylinder, 250,000 circular mils. At first only 

 India-rubber insulation was used, but last season paper was 

 tried, so that now there is about an equal division, or 25 miles 

 of each type of insulation in use. 



In the rubber cable each conductor is insulated with „% of 

 an inch rubber insulating wall. The three conductors are then 

 laid with jute and made into a cable of circular section and an- 

 other jacket of rubber put on, ^\ of an inch in thickness. The 

 rubber compound is 30 per cent, pure Para. The lead is | inch 

 thick, 3 per cent, tin, but with no outside coating of tin. This 

 gives a cable 2| inches outside diameter, and the experience 

 from laying 50 miles of cable would indicate that this is the 

 largest practical cable that can be installed in a commercial 

 3-inch duct. The insulation resistance required on the rubber 

 cable was 1000 megohms per mile, measured either between 

 conductors or between conductor and lead. The completed 

 cable was tested to 20,000 volts in the ducts. 



The paper cable was similar, but with 3% inch more insulation 

 in the outer jacket, making J| inch insulating wall in all direc- 

 tions. Insulation resistance required on this was40o megohms 

 per mile. The paper cable measured 25^ inches outside diam- 

 eter, and although it has all been installed, yet it was drawn 

 through the 3 inch duct with difficulty ; and one would not ad- 

 vise attempting it again, as it was a great mechanical strain on 

 the cable. The natural question in the minds of many is, 

 which is better.' It is proper to say that satisfaction has been 

 obtained with both. 



The above details are derived from a paper read by Calvin 

 W. Rice before the National Electric Light Association at 

 Niagara Falls. 



RUBBER TIRES ON FIRE ENGINES. 



SPEAKING of rubber tires, somebody in the tire trade is 

 quoted in the New York Sun to the effect that there are 

 twice as many vehicle tires in use to-day as there were two 

 years ago. 



" There's a good big bunch of rubber tires in use in the fire 

 department," the tire man continued. " I guess that in Man- 

 hattan and Brooklyn boroughs you would find a dozen or more 

 engines thus equipped, and the new engines bought are thus 

 provided. Then there are some hook and ladder trucks with 

 rubber tired wheels, and a good many hose wagons. 



" A fire engine is heavy, the wheels are big, and they must 

 have big tires which cost money. A set of rubber tires suita- 

 ble for use on a fire engine costs in fact from $400 to $450. 

 There is no question about the advantages of their use here. 

 With rubber tires an engine goes less often to the repair shop, 

 and so is more continuously in commission. And if you 

 should happen to see a rubber tired engine go around a corner, 

 or get into or out of the tracks of a street railroad, you'd think 

 the advantage gained there was enough to pay for the tires. 

 The engine doesn't swing or slide, but it follows true and the 

 driver knows just where he can go and what he can do with 

 the machine when he's under way. 



" I should say that it would be profitable for the city to use 



these tires on its engines at practically any cost, but it wouldn't 

 surprise me to learn that, costly as they are, what with the ma- 

 chinery carried and all, the use of the tires results in an actual 

 economy." 



BUTTON HOLES IN MACKINTOSHES. 



ONE of the most perplexing problems that confronted the 

 manufacturer in the earlier days of mackintosh making 

 was button holing the garment. The large number of button 

 holes required made a large force of hands necessary and, be- 

 sides, it was essential that the work should be strong, with good 

 wearing qualities, and also that it should be of handsome 

 appearance. The nature of the material rendered it very diffi- 

 cult to produce button holes possessing these qualities and im- 

 possible to do so at all, except at extravagant cost. 



The use of the Singer Manufacturing Co.'s button hole ma- 

 chine (No. 61-4, in its present improved form) has happily solved 

 this problem. Its use in mackintosh factories is now practically 

 universal. It produces button holes of uniform excellence in 

 durability and in appearance so rapidly as to reduce the cost to 

 a minimum figure. 



The machine is fitted with an automatic cutter (which alone 

 effects a saving of from 25 to 30 per cent.), automatic stop, foot 

 presser, and in fact with every improved device for adding to 

 the convenience of the operator, enhancing production, and 

 improving the quality of the work. 



The positive simplicity and durability of the mechanism and 

 the fact that it can be successfully used by any intelligent sew- 

 ing machine operator has made this machine very popular with 

 manufacturers. A view of the machine appears in the adver- 

 tising pages of this issue. A sister machine (Singer No. 16-69), 

 specially arranged for sewing buttons to mackintoshes, exten- 

 sively used in some of the best factories, together with other 

 productions of the same company, will be noticed in future 

 issues of The India Rubber World. 



RUBBER SHOES IN THE WORLD'S TRADE. 



THE exports of rubber boots and shoes from the United 

 States during the first six months of 1901 have been 

 treated elsewhere in this paper in detail. The total was 386,657 

 pairs. During the same period there were exported by Great 

 Britain 660,732 pairs. The German statistics give only weights 

 — 286,220 pounds for the six months. The values officially 

 stated are : 



United States $200,952 



Great Britain ;f 73,261= 366 ,305 



Germany .A/7i6,ooc^ i7g,ooo 



The values given above average 52 cents per pair for Ameri- 

 can goods and 2.?. 2j^</. for British, or about 53 cents. The 

 greater part of the American exports in this line go out usually 

 in the latter hall of the year, no fewer than 1,122,443 pairs hav- 

 ing been exported between July i and December 31, 1900. It 

 remains to be seen whether a similar rule holds with regard to 

 the other countries named. 



The distribution of the German exports was : To Great Bri- 

 tain 69.2 per cent.; Belgium 6.7; France 5.7 ; Denmark 1.5; 

 other countries 16.9 per cent. The imports of rubber foot- 

 wear into Germany for the six months amounted in value to 

 2,556.000 marks (= $639,000). Calculating by weight, 83.2 per 

 cent, of the whole came from Russia, 10.9 per cent, from the 

 United States, 4.1 per cent, from Great Britain, and the re- 

 mainder from other countries. It would appear, therefore, 

 that Germany took $531,000 worth of Russian rubber shoes. 



