nearly seven miles high and nearly died from the cold. Mr. Glaisher himself fainted: his companion, Mr. Coxwell, wished to open the valve so that the balloon might descend, but found that his hands were frostbitten: however, he managed to climb up with his elbows and knees and open it with his teeth, and then they dropped quickly to a warmer region and revived. Mr. Glaisher's object in making these ascents was to find out the temperature and pressure of the upper air, for which purpose he carried up a whole trayful of instruments: and he did find out a very great deal—practically all we knew until recent times. But since seven miles was the highest he ever went, we knew nothing at all about the air above that point. We could only guess, and we guessed quite wrong.
And now we come to the balloons that have really taught us about the upper air, about which the people who study the weather have been trying to learn for years, and have at last succeeded. First of all they tried by sending up kites of a peculiar shape: you see a fine specimen up there. They are not like ordinary kites, but are in the shape of a box almost; but they have been copied in the form of toys, and perhaps this one does not seem so strange to you as it would have to us in our childhood. These kites can be got up to great heights by attaching one to another in a series. The top kite has been up above the aeroplane record, but not so high as the man-balloon record. They do not, of course, take up men with them, but they carry a recording apparatus, including a barometer and thermometer. The thermometer is that curious spiral spring at the back.
