National Geographic : 1936 May
SCIENTIFIC RESULTS OF THE STRATOSPHERE FLIGHT high - pressure condition, result ing in low air velocities in the lower levels of the atmosphere, also results in low velocities in the stratosphere, is debatable. It also hap pens that most of our sounding bal loon observations are apt to give moderate wind velocities in the stratosphere, be cause sounding balloons can be observed at levels of 40,000 to 80, 000 feet by tele scopes onlIy on days that are fairly clear. Such days more often exist when there are high - pressure conditions, which are exactly the sort of days upon w h ich strato s ph e re flights must be made. On days when a low-pressure con dition exists, clouds are apt to be overhead, thereby prevent ing the following of sounding bal loons by tele scopes. When there are Photograph by Edwin L. Wisherd ANALYZING STRATOSPHERE AIR-TOO THIN FOR ANY LIVING THING TO BREATHE AND LIVE Some of the extremely thin air of the stratosphere at 70,000 feet above the earth was trapped by allowing it to rush into six-gallon containers, through valves in the gondola wall. Two containers, pumped free of all air before the flight, and sealed, here are mounted on top of apparatus for air analysis at the National Bureau of Standards, with G. M. Shepherd conducting the tests. Preliminary results indicate that air at 70,000 feet above sea level contains proportionately slightly less oxygen than air at the surface of the earth, but its composition does not differ as much from the air we breathe as some scientists had expected (see page 703). extremely high velocities in the stratosphere, a sounding balloon may drift so fast as to be beyond range of a telescopic station before the balloon has attained a level as great as that achieved by Explorer HI. On Commander Settle's flight there was such a wind velocity in the stratosphere that, after he reached that region, he drifted from a point near Akron, Ohio, almost to the Atlantic Ocean, a distance of 350 miles in less than five hours. On the day that Commander Settle ascended there was practically no wind, all day long, on the ground. It was an Indian summer day, cloudless and extremely hazy. Yet on this day there was a great air move ment aloft. This haze, on the day mentioned, was confined to the lower level of the atmos phere, and once Commander Settle got to 15,000 feet the air was quite as clear as it was on our flights.