February i, 1909.] 



THE INDIA RUBBER WORLD 



183 



her cloth similar to that already referred to — diagonal thread- 

 but without an inner layer of rubber, since the makers do not 

 fear damage from impurities in the hydrogen gas. 



The balloon fabric used on the airships and balloons men- 

 tioned thus far is of German manufacture. The subject of mili- 

 tary aeronautics has been taken up in earnest by the signal corps 

 of the United States army, with results of real interest, not 

 the least important of which is the success achieved in the manu- 

 facture of balloon fabric in this country. The fabric used for 

 the dirigible balloon accepted by the government from Captain 

 Thomas S. Baldwin, of New York, is made of two layers of 

 Japanese silk, with a layer of vulcanized rubber between, and 

 this was supplied by a leading American rubber manufacturer. 

 The gas bag used by Captain Baldwin is 96 feet long, with 

 a maximum diameter of 19 feet 6 inches, and a volume of 20,000 

 cubic feet. 



Some details of the size of the more notable air ships may 

 give an idea of the amount of fabric required for their con- 

 struction: 



Patrie cubic feet 111,250 



Republique 131 ,000 



Ville de Paris 112,847 



English Military Dirigible No. i 84,768 



■Gross (German) 63,576 



Parseval 1 13,000 



Zeppelin (16 gas bags) 460,000 



The surface measurement of these is not given, with the ex- 

 ception of the "Ville de Paris," the envelope of which has a 

 surface of 19,676 square feet. 



* * * 



The following is an extract from a letter to The India Rubber 

 World by Captain Thomas S. Baldwin : 



"I have read carefully an article in your October issue on 

 'Aeronautics and the Rubber Industry.' It was very good, but 

 you did not bring out the strong points of the vulcanized proof 

 material, .^s a matter of fact the rubber material is lighter 

 in weight than the varnished material, and also it will stand 

 liny degree of cold. Many such things as that is what makes it 

 the coming material for balloon purposes. 



"I am very glad to see your paper take the interest in it that 

 you have, as it will all do its help toward the ultimate using of 

 rubber fabric for balloon purposes. 



"I have seen the aeronauts of the middle west, and it is fear- 

 ful the 'knock' they are putting up against the rubber fabric, 

 principally on account of the price, but we will gradually over- 

 ■comc this objection. 



"In i8gi and 1892 The India Rubber World assisted me very 

 materially in getting the data for this very same material, and I 

 have always felt very kindly toward it." 



* * * 



To THE Editor of The India Rubber World: In reference 

 -to rubberized balloon material, we are using the French, German 

 and American made materials. This material is not new, by any 

 means ; it has been in existence for the past ten years, and its 

 great cost is its drawback. There is no great advantage of this 

 material when it is taken into consideration that the ordinary 

 unvulcanized rubber and varnished materials mi.Kcd stand five 

 or six years' wear, and the balloon is usually ripped up before 

 being decayed. It is true that the rubberized materials are a 

 little stronger on account of their double and triple thickness 

 material, but the weight added thereon robs them of their ascen- 

 -sional growth. a. leo stevens. 



New York, January 5, 1909. [Balloon Constructor.] 



HERR PRINZHORN ON PLANTATION RUBBER. 



Dr. John C. Willis, director of the royal botanic gardens 

 of Ceylon, in a note to the Ceylon Observer, says that he has 

 always been against the tapping of cultivated Hevea before the 

 fifth or sixth year, and that he considers all rubber trees under 

 ten years young trees. 



THE rubber planting regions of Malaya and Ceylon are being 

 visited at present by Herr Adolf Prinzhorn, managing 

 director of the Continental Caoutchouc- und Guttapercha- 

 Compagnie, of Hanover, Germany, who has expressed a great 

 interest in the progress of rubber culture, though it does not 

 appear that he has invested any capital in it, at least in the Far 

 East. In an interview with Herr Prinzhorn the Ceylon Observer 

 reports him, in part, as follows : 



"Para rubber has gone up 60 per cent, since March," said Mr 

 Prinzhorn. 



"What are the causes?" 



"It would be better if you asked me What it declined previously 

 to then. It was, to a great extent, due to the American crisis. 

 The American factories were working only half-time in many 

 cases, whereas they are now working full time. The price was 

 2s. gd. then — ^much too low — and it is now about 5.?., which ij 

 much too high. I should think a fair normal figure would b« 

 3s. 6d. to 4s. a pound. While it is as high as at present there ij 

 not likely to be any increase in the uses of rubber." 



"What will bring the price down?" 



".•\n increased output of plantation rubber, every ounce of which 

 that is sent over to Hanover, sells. Yes, I think the German 

 manufacturers like plantation rubber. We can use it for most of 

 the articles that we manufacture, though not all. I think that the 

 best Ceylon rubber is equal to .fine Para. Ceylon rubber is liked 

 generally." 



"In what form is it preferred?" 



"Well, that is difficult to say, crepe or dry blocks." 



"Will the present good demand for rubber be maintained?" 



"Yes, I think so ; there is every reason for it doing so. It is 

 partly speculation that causes the fluctuation in prices, so far as I 

 can see. If the output becomes largely increased and the price 

 comes down, of course, many new uses for rubber will be prac- 

 ticable and the many substitutes for rubber which are on the 

 market will disappear." 



"Where do you buy your rubber, Mr. Prinzhorn?" 



"I buy in the cheapest market. When I can get it cheaper in 

 New York, I buy it there; if in London, then in London I buy. 

 We use something like 200 tons of rubber a month in our factory." 



In an editorial note The Times of Ceylon remarks upon the use 

 of 200 tons of rubber per month by Mr. Prinzhorn's company, 

 whereas the average monthly export of plantation rubber from 

 Ceylon has not yet exceeded 28j4 tons. The Times says : "The 

 fact that one manufacturing firm alone consumes about seven 

 times as much as this island produces will go to show what little 

 influence on prices our rubber can have at present. Even for 

 1910, Mr. H. K. Rutherford's estimate of the output of Hevea 

 rubber of the whole of Asia is 3,520 tons, as compared with 2,400 

 tons used by this one company of manufacturers." 



Mr. Prinzhorn mentioned in an interview for the Times a 

 marked improvement in plantation rubber now as compared with 

 a few years ago. He had recently seen samples of plantation rub- 

 ber equal to the best Para. It was being used in his factory for 

 nearly all purposes for which Para is employed. 



A GOVEKNMENT RUBBER PLANTATION. 



Bids were invited by the conservator of forests for Eastern 

 Bengal and Assam (India) up to January 15 for produce of 

 the government rubber plantations of Charduar and Kulsi for 

 the fiscal year 1908-09, estimated at 12,000 pounds for Charduar 

 and 4,000 pounds for Kulsi. .^t Charduar exists one of the 

 earliest rubber plantations in the world, systematically laid 

 out, and no other was ever written about so extensively. 

 It was purely a government undertaking for experimental pur- 

 po.ses, and is still practically so. The rubber species is 

 Ficus clastica, and the enterprise has no connection with the 

 introduction of Hcren into Ceylon and Malaya. 



