Article October 9, 1902 Issue

Temperature of the upper Atmosphere

The Boston Transcript

Some of the records obtained with balloons are striking. In October, 1895, a free balloon sent up from Paris, reached the height of forty-six thousand feet,—nearly nine miles,—and at this point a temperature of ninety-four degrees below zero, Fahrenheit was recorded, probably the lowest natural temperature ever recorded. A German balloon, in 1894, reached the unprecedented height of 60,500 feet, shown by a barometer column of two inches in length. The lowest temperature recorded was eighty-eight degrees below zero, F., probably a false record due to heating of the instruments by the sun. This balloon traveled five hundred and sixty miles in a northwesterly direction from Berlin, at an average rate of eighty-three miles an hour.

Ingenuity has surpassed itself in attempts to avoid the false temperatures due to insolation, or sun-heating, of the balloon instruments. This is because, with the usual form of balloon (open at the bottom), the balloon moves more and more slowly as it approaches its greatest height. Closed balloons of elastic material, on the contrary, rise with increasing velocity until they burst, and the errors due to insolation are greatly reduced. A balloon invented by Dr. Assmann is made by dipping a mould into a solution of India-rubber. This case was expanded to sixty-eight times its original volume before it burst, showing that it would have risen to a height of about eighteen miles. Balloons of this type are provided with a small parachute, so that when the case bursts, the instruments fall to the ground without damage.—The Boston Transcript.

Send a comment to the editors

NEXT IN THIS ISSUE

Article

The Cause of Lightning