172 



THE INDIA RUBBER WORLD 



[February i, 1910. 



THE HODGMAN BALLOON FABRICS. 



WHILE the conquest of the air by man cannot be said to 

 have been accomplished as yet, the progress made in 

 aeronautics during the past year or so has been so marked 

 that this must be admitted to have become a practical field for 

 human endeavor. Not only this, but the new science, or sport, 

 or whatever it may be termed, has attracted already a wider 

 place in human interest than has ever been the case in the same 

 length of time with a new invention or discovery in the history 

 of the world. The interest to the rubber trade of the develop- 

 ment of aeronautics, as has been pointed out in these pages, is 

 due to the fact that rubberized fabrics figure already to so 

 large an extent in the construction both of aeroplanes and bal- 

 loons, and the results obtained from the use of rubber in this 

 connection have been so satisfactory that the employment of 

 other fabrics is likely to decrease rather than become larger. 



It is gratifying to Americans that their countrymen have won 

 so large a share of success in the new field. On account of 

 Americans having been winners in two of the important inter- 

 national contests in aeronautics last year, the prizes won, under 

 the rule, must be contested for this year in the United States, 

 a fact alone which will tend largely to develop American interest 

 in such matters. 



The names of some important European rubber manufacturers 

 have been mentioned in The India Rubber World as producers 

 on a large scale of fabrics for balloons and flying machines. 

 The American rubber industry has not been backward in making 

 fabrics for the same purpose. It will be remembered that the 

 last formal dinner of the Rubber Club of America, in Boston, 

 in December, was termed an "aeronautic symposium," which was 

 an indication of widespread interest in the rubber trade in 

 aerial flight. The handsome menu card was embellished with 

 views of notable machines for air flight, the fabric for which 

 was manufactured by members of the rubber trade present at 

 the dinner, though no public reference was made to this fact. 

 The fact can be stated here, however, that the balloons which 

 Captain Thomas S. Baldwin has sold to the United States 

 government — a large dirigible and several sphericals — as well 

 as the other balloons made for him have been constructed with 

 the use of fabrics waterproofed by the Hodgman Rubber Co., at 

 their factory in Tuckahoe, N. Y., being made at that place under 

 Captain Baldwin's supervision. The Hodgman company and 

 Captain Baldwin are associated in the further development of 

 the use of rubber coated fabrics in the manufacture of balloons 

 in the United States. 



One of the best known products of this association is the bal- 

 loon "New York" sold to Mr. Clifford B. Harmon, which won 

 the American record for duration in a balloon flight, starting 

 from St. Louis at the time of the centennial celebration in that 

 city, in October last. Harmon remained in the air 48 hours and 

 26 minutes — the second longest official flight ever made. 



In this same balloon Mr. Harmon, with Mr. Augustus Post, 

 secretary of the Aero Club, reached the great height of 24,200 

 feet in the fall of last year, whii h is a testimony to the gas 

 retaining qualities of a rubber coated fabric. 



The Hodgman company also are manufacturers of the fabric 

 used in the Curtiss biplanes, including the machine with which 

 Glenn H. Curtiss won the Gordon Bennett international aviation 

 cup at Rheims. last August. 



The balloon "New York," guided by Mr. Harmon, made a 

 good record at the International Aviation Meet at Los Angeles, 

 California, during the month just past, making an ascension 

 of 10,000 feet. The same is true of the Curtiss machines at Los 

 Angeles, which won the prizes for speed, quick starts, perfect 

 landings, and those events where a light swift machine showed 

 best. 



The Hodgman company have pursued a different course from 

 some other members of the rubber trade, in that their fabrics 



for balloons are not offered to the trade generally, but are sup- 

 plied only for use where the construction is under their own 

 supervision, it being deemed best at present not to risk failure 

 in the use of their fabrics through careless or inexperienced con- 

 struction work outside of their control. 



At the factories of the Hodgman Rubber Co. have been car- 

 ried out an exhaustive series of experiments with regard to 

 the fabrics to be used for certain strains or pressures, and the 

 proper quality of waterproofing in each case. So careful have 

 these experiments been that even the best color for balloon 

 fabrics, for instance, has been studied. Not all the aeroplanes 

 in use are made with waterproof fabrics, but it is coming to be 

 recognized that a plane waterproofed with rubber is superior to 

 one of unproofed cotton, which is liable in rain to shrink; be- 

 sides it has been suggested that a properly surfaced rubber 

 coated fabric is smoother than any other and thereby minimizes 

 resistance to the air. 



CANKER IN PARA RUBBER. 



"""HUE original "canker" of Hevea has not been much in evi- 

 ^ dence during the last three or four years, but several cases 

 were notified during the prolonged rainy season of this year 

 (1909), and the subject is being investigated. It has been 

 determined that probably in the majority of cases the deatli of 

 the bark in patches after the tree has been scraped before 

 tapping is due to "canker," sometimes assisted by deeper scrap- 

 ing than should be allowed. But the most general symptoms 

 exhibited during the current year differ completely from those 

 previously recorded. The disease attacked the renewing bark 

 on the surface which was being tapped. The bark showed 

 numerous vertical black lines, and on cutting it out these lines 

 were found to extend into the wood. These black lines may be 

 found on the cambium before they are evident externally. The 

 hark round these lines decays, leaving a narrow vertical wound. 



Sometimes adjacent patches coalesce, and the whole of the 

 renewing bark decays. In most cases the disease does not 

 extend downwards as rapidly as the bark is exercised during 

 tapping, and it is therefore possible to continue tapping although 

 the tree is diseased. With the advent of drier weather the 

 disease stops and the bark renews over the wounds, but as it 

 has to grow in from the edges of the vertical wounds, the re- 

 newed bark is rough. Except for this rough bark, there is no 

 permanent injury to the tree. 



The cause of Hevea canker cannot he said to have been 

 determined. Four organisms have been found fairly regularly 

 in the diseased tissue. Two of these are in all probability only 

 saprophytic and are not being considered at present; the other 

 two are a bacterium and a Nectria. The evidence of the diseased 

 tissue seems to point to the bacterium as the cause, since 

 it is always found in advance of the hyphae of the Nectria, and 

 the discoloration of the wood is identical with that in the bac- 

 terial cultures. But inoculations with both these organisms have 

 so far been unsuccessful. 



The bacterium has been isolated and grown in pure cultures, 

 but an attempt to produce "canker" by inoculating tapped sur- 

 faces with bacteria from these cultures has proved a failure up 

 to the present in the case of the Nectria, the ripe spores were 

 caught as they were ejected from the fructification, and these 

 were proved capable of germination by sowing them in culture 

 solutions ; but no success has yet followed the inoculation with 

 these spores. — T. Petch, b.sc, b.a., in Tropical Agriculturist. 



Between Para and Manaos it is stated that more than 100 

 large steamers are engaged in carrying rubber and other cargo 

 and passengers on the Amazon, the waters of which are fur- 

 rowed by the keels of innumerable smaller steam vessels and 

 sailing craft, not to mention canoes between points only a -small 

 distance apart. 



