366 



THE INDIA RUBBER WORLD 



[August i, 1908. 



5 months of several years past, is derived from official puljlica- 

 tions of the two countries : 



America. Germany. 



January-May, I1J05 pounds 173.345 (a) 



January-May. igoo 1,056,595 133,320 



January-May, 1907 3,939.^38 1,002,320 



January-May, 1908 3.894,041 1,085,040 



[(J — Not reported.] 

 The large figures given above would seem to justify the pre- 

 dictions to be heard on every hand that the production of 

 guayule cannot last for many years, since the limits of supply 

 have been pretty well outlined. 



INSULATED WIRE SATURATING TANKS. 



COMING in daily touch with the conditions and methods 

 adopted by numerous wire manufacturers in the application 

 of wax to the braid of an insulated wire, we have noticed that a 

 great man\" troubles are traceable directly to the saturating tank. 



The heavy first cost of building a saturating tank out of boiler 

 plate, coupled with the danger of explosion due to getting the 

 steam to too high a pressure in the steam chest used in this 

 style of construction, forced us to the conclusion that although 

 it was, theoretically, the ideal way to build, in actual practice it 

 had its faults. Then again, when a tank built with steam pipes 

 is located inside the vessel proper, although overcoming explo- 

 sion trouble, it is next to impossible to remove the sediment 

 which is bound to settle and burn to the tops of the steam pipes. 

 After several months' use, this last acts like an asbestos covering, 

 preventing the heat from freely radiating into the wax, and re- 

 sulting in the compound taking twice as long in heating up in the 

 morning, so that the first coil saturated in a run frequently shows 

 that the braid has not been thoroughly penetrated. 



To keep this tank in condition is both annoying and costly, 

 necessitating the taking apart, removal, and burning of the steam 

 pipes whenever the sediment, burned to the outer surface of the 

 pipes, forms a crust, preventing the heat from freely penetrating 

 the wax. The annoyance of this last is known to the sorrow of 

 many manufacturers, especially those who have made wire for 

 the government under specifications calling for a certain per- 

 centage of sea sand to be incorporated into the wax covering. 

 The non removable type of drum around which the wire is 

 wound and then revolved in the molten wax has many objec- 

 tions, the chief of which is that, the drum being entirely im- 

 mersed, workmen oftentimes get badly burned repairing a wire 

 that has broken in the process. 



Having the above in mind, the writer has designed tanks in- 

 volving details as follows : Some of the ideas, of course, have 

 been incorporated successfully in the construction of tanks for 

 years, but there may be enough that is new here to prove of 

 interest. In designing, we had in view a tank so constructed that 

 it would heat the waxes quickly and evenly, permit of maximum 

 speed in application, be safe in operation, make it possible at all 

 times to get at the wire in case of a break in the hot wax, give 

 results that are uniform under all conditions, permit of easy, 

 effective, and economical scraping to remove any sediment tliat 

 may form on the tank's sides and bottom, and at the same time 

 be inexpensive to construct and low in cost of maintenance. 



A wooden chest is first built — oak preferably, and the sides, 

 ■ends, and bottom lined with a double thickness of asbestos felt. 

 Around the sides of the chest proper ij^-inch steam pipes are 

 encircled. These are supported on angle iron frames so placed 

 that there is at least an inch of space from the inner surface of 

 the asbestos felt. The arrangement of the pipes is' such as to 

 permit the attachment of automatic steam traps to free the pipes 

 of condensation. An inner tank is then built of sheet iron, made 

 lap seamed and riveted .so that it is fluid-tight of a size that will 

 set into the space and rest on the steam pipes side and bottom. 



The upper edge is flanged sufficient to allow it to be securely 

 fastened to outer wooden one. In doing this the space occupied 



by the steam pipes is sealed, making practically a dead air space 

 backing. 



Two general types to accomplish these results are possible — 

 I. e., those having but one reel over which the wire passes, and 

 those with two. The special advantage of the single reel is 

 that it occupies little room, as in this method of con- 

 struction the box proper is generally made only large 

 enough to permit of easy working of the reel in the wax. 

 Treating as it does but one wire at a time, the time lost in re- 

 pairing a broken wire is reduced to a minimum. The circum- 

 ference of the single reel being larger than in the double reel 

 construction, there is less liability of injuring the insulation of 

 die braid, caused sometimes by bending a lieavy gage wire 

 around the circumference of a small drum. 



In the double reel construction the outside dimensions of the 

 tank are usually much longer and narrower than when one reel 

 is used. The cubic space inside this style tank being large, it 

 permits the adding of unmelted wax in cakes as required without 

 affecting the temperature of the molten wax. It being possible to 

 treat as many as a dozen wires or more at a time in tanks of this 

 construction, it is possible to give the wire a larger time in the 

 wax than in the single reel construction, and still have the daily 

 output more than by other arrangement. This insures thorough 

 saturating, a very important feature when the life of botli braid 

 and rubber insulation is considered. 



It is readily seen by this rough description that tanks so con- 

 structed are very inexpensive, and that practically all the heat 

 generated in the steam pipes is imparted to the wax. Owing to 

 the dead air space obtained by using the asbestos felt, and the 

 fact that the sheet iron is of thin gage, the heat is not retarded 

 as it is in passing through the thick boiler plate necessary in the 

 steam chest construction. The sides of the tank being smooth, it 

 is an easy matter to scrape and clean. The face of the reel should 

 be slatted to allow free circulation of melted wax around the 

 wire during treatment. The reel itself should revolve on a shaft 

 which is fastened at either end to two flat iron supports, which 

 last are suspended from either side of the tank. One of these 

 supports should have attached a handle of sufficient length and 

 strength to permit of turning the reel upside down out of the w-a.x. 

 to enable getting at the wire to repair in case of break. 



\\. C. C01.F.M.\N. 



PROGRESS OF WIRELESS TELEGRAPHY. 



jV/IARCONI'S Wireless Telegraph Co., Limited, during June 

 '■''■ offered for public subscription £250,000 in additional shares, 

 the proceeds to be used in establishing a service between Poldhu 

 and the United States, to supplement their present transatlantic 

 service between Galway and Canada. The authorized capital of 

 the company is £750,oco [=$3,649,875], and the previous issue 

 of shares amounted to £394,190. The company states that it 

 has large holdings in several affiliated companies, besides owning 

 over 400 wireless telegraphy patents and a factory for producing 

 the apparatus used in the Marconi wireless system, all of which 

 constitute a source of revenue in addition to that of the direct 

 operations of the company first named. Concerning the affiliated 

 Marconi International Marine Communication Co., Limited, the 

 following figures are given, in respect of its maritime business : 

 Number of ships (other than warships) using the Marconi sys- 

 tem, :i8; number of words transmitted in 1907, 1,834.540; net 

 receipts from this source, £37,506 6s. ^d. 



The purchase from Bolivia of the Acre district appears to 

 have been a profitable piece of business for Brazil, The in- 

 demnity paid, exclusive of the cost of the Madcira-Mamore rail- 

 way, now building, was £2,000,000 (£2,050,000. including bank- 

 ers' commissions). Up to the end of 1907 more than this much 

 was received by the Brazilian government in duties charged on 

 the export of rubber from the .^cre district. 



