Exploring the Upper Regions of the Sky
A STRING of six kites sent up from the German Aeronautical Observatory at Lindenberg recently attained an elevation of twenty-one thousand and ninety-six feet, or almost exactly four miles. This is the highest elevation yet reached by kite flying, and it illustrates remarkable progress during the last two or three years in this method of investigating the conditions in the upper air. Three years ago a height of from two to two and one-half miles seemed to be the limit of attainment for kite flying, but there has been steady improvement in the forms of kites and the methods of handling them. The present achievement is all the more noteworthy because it was made on land, where the kites were influenced only by the natural winds. Judging from the work of last summer at sea, the prospect is that still higher kite ascensions will be made this season over the Atlantic, where vessels may steam against the direction of the upper air currents and force the kites to still higher altitudes. The temperature and wind velocity records of this ascension were very interesting. The thermometer registered at the surface forty and eight-tenths degrees Fahrenheit, but it dropped at the highest point attained to minus thirteen degrees. The wind rate in the lower stratum of the air was eighteen miles an hour, but a fair gale was blowing aloft, where a velocity of fifty-six miles an hour was recorded. Much higher altitudes are made by the little rubber balloons that the Germans and French are making for high air exploration. One of the balloons sent up at St. Louis last year, under the direction of Mr. Rotch, the director of the Blue Hills Observatory, recorded a height of forty-eight thousand seven hundred feet, with a temperature at that elevation of minus one hundred and eleven degrees. The lowest temperature ever recorded at the surface of the earth was about minus ninety degrees near the Siberian pole of greatest cold. When the dog-days come again, we may derive such comfort as is possible from the thought that only a few miles away a degree of cold is reigning that surpasses anything known in the polar regions. A difficulty with the balloons is that they are likely to drift far away from the starting-point, and may never be recovered. One of the St. Louis balloons was found two hundred and eighty-five miles from the place of ascent; but an ingenious invention was tested over the Mediterranean and the Atlantic last summer which promises greatly to increase the efficiency of these appliances. Two balloons are connected by a light cord about one hundred and fifty feet long. After reaching a great height, one of the balloons, which had been more heavily inflated than the other, bursts on account of the greater expansion of its gas. When the wreck reaches the surface, the other balloon is still one hundred and fifty feet in the air, preserving the records and serving as a guide to the place of descent. Thus the means of exploring the upper air are constantly improving, and the work will be carried on this year with more enthusiasm and energy than ever. Clouds indicate air movements only in the lower strata of the atmosphere, and we knew very little of what is going on above them until high kite flying was introduced. Meteorological science has been considerably advanced by this new phase of exploration. The fact need only be mentioned here that the great result of Mr. Rotch’s expedition to the tropical Atlantic, north of the equator, last summer was the indubitable proof it secured that above the northeast trade wind a counter current (or, in other words, an anti-trade wind) is a persistent phenomenon of those regions.—N. Y. Sun.