2,000-BALLOON POWER

Evening Star, Issue 22798, 5 November 1937, Page 12

2,000-BALLOON POWER

DR PICCARD'S MEW PLAN HOPES TO REACH TWENTY-MILE MARK It was at the circus that ballooning got its start in former days, and recently Dr Jean Piccard, one of the world’s foremost stratosphere scien J tists, “ went back to' the circus ” .to learn a few tricks modern ballooning has almost forgotten. Where is the circus-loving boy, for instance, who has not at some time dreamed of tying a flock of red, white, and blue hydrogen-inflated balloons together for a sail above the clouds? That is just what Dr Piccard is thinking about to-day, but because he happens to be a practical-minded physicist, he plans to use stouter balloons than the circus variety. Nevertheless they will be made of rubber, 2,000 of them all tied together on a boss of metal, beneath which will be attached his closed gondola, and when the flight takes place, Mrs Piccard will again sail with him This is no idle dream. Dr and Mrs Piccard were both in Cambridge talking over technical details with engineers at the Dewey Almy Chemical Works, makers of the Darex balloons, which he used once before in a test flight to 11,000 ft and which he will use again when he sets out for the 20-mile mark—straight up—his gondola loaded with scientific instruments. Another practical item—the cost of financing such a flight—seemed clearer.. It was Mrs Piccard who thought of that, and her suggestion was to sell shares in the expedition at £2O a share, printing the name of the individual sponsors on the balloons, each to be sent to its “ owner ” when the flight is over. Thus each sponsor will have a souvenir that “ went higher than Piccard.” Dr Piccard promises to bring back 90 per cent, of the balloons intact, _ the rest will necessarily be destroyed in the descent.

His most recent flight, in which he investigated the possibility of using small balloons in place of one large one for stratosphere work, was made on July 17. On this occasion he used approximately 80 balloons of the type employed by meterologists for investigation of weather conditions in the higher atmosphere. The balloons were hitched to a specially constructed gondola christened the “ Pleiades.” For this flight, metal punehings were used as ballast to control the ascent of the strange craft. It is estimated that the total lift of the balloons was in the neighbourhood of 400 pounds. Dr Piccard, in commenting on his test flight, stated that the balloons' “ behaved beautifully.” The ascension was made at midnight from Soldiers’ Field, Rochester, Minnesota, in a prowshaped aluminium gondola carrying scientific instruments and a two-way radio. Half of the 80-odd balloons were in a cluster 57ft above the gondola, and the other 40, floated 50ft above this tier. <( I rose rather slowly to an altitude of about 11,000 ft,” he said, “ where I stopped further ascent by cutting loose a few of the balloons. For about three hours I floated in a state of practical equilibrum, but at dawn, seeing that I was near the Mississippi River and dense fog banks, I decided to descend. I pulled the balloons down on the strings this time, and punched them with my hunting knife. I this way I came to land in a small canyon, shooting a dozen or so balloons with my revolver at the last minute to hasten the descent.” . As soon as the gondola was on the ground he released the top cluster of balloons by exploding a previously prepared charge of TNT. It was the excelsior in which the TNT had been packed which caught fire and fell into the gondola, setting firo to it and destroying the instruments. . “ I am, however, decidedly'pleased with the ease with which the whole aircraft was controlled,” Dr Piccard declared. “ This accident at landing was one which would not ordinarily occur and which can easily be prevented in the future by using rockwood instead of excelsior.” “ You spoke of * string \ being used to connect the balloons with the gondola, no doubt you mean a stout wire,” somebody commented at the interview. “ No, I didn’t use wire.. However, yon couldn't really call it string,” smiled the professor. “ It was ordinary Irish linen thread of the 10-cord variety. I tested the strength in my laboratory and found it has a very high breakage point, well within the necessary limit for safety.” Another surprise came when methods of inflation were talked of. . “ I can inflate my balloons and get off the ground in a very few minutes,” he said. “ This is not so of the large, single-bag type of craft. “ Furthermore, the small balloons permit aifceconomical method of lifting. A fabricated balloon bag, suitable for

an ascent into the stratosphere, would cost around £30,000, whereas with 2,000 Darex meteorological balloons the cost will only be around £1,700.” These balloons are cast from liquid latex by a newly developed and patented process-in relatively small size. The finished balloon has a diameter of about four or five feet and is capable of expanding to some 20 feet in diameter before bursting. It is this ability to expand easily which provides the necessary lift for the craft. There is very little difference in pressure between the gas inside the balloons and the air outside, but the balloon stretches so readily that as it rises and the pressure of the atmosphere becomes less,’.the gas inside expands until" the balloon wall is hardly thicker than the -thickness of the rubber molecule. At this size it becomes transparent and has expanded to four or five times its original size. For inflating the individual balloon* Dr Piccard has invented a small glass stopper which fits in the balloon nozzle, can be fastened with thread, and speeds the former process of inflating and tying tremendously.