But they were more than free. They were suddenly in profound repose, for—however high the wind may be, however agitated the balloon, swaying to and fro with sudden and violent action, despite the efforts of many hands that endeavour to restrain it,—no sooner do aeronauts quit their hold of earth, than, in an instant, all agitation ceases and they are in perfect stillness, without any sense of motion whatever; and this freedom continues throughout the entire flight—except, indeed, when they sink so low as to come into contact with mother earth, when the serenity of their flight is terribly and violently interrupted, as shall be seen in the case of another balloon voyage hereafter to be described.
They were now fairly away, but we pause to remark, before joining them in their voyage, that their object on this occasion was not merely amusement—scientific investigation and experiment were their aim. In order that the reader may have some idea of the nature of such, we subjoin Mr Glaisher’s list of the objects of his experiments:
The primary objects were, he says, “to determine, at various heights, up to five miles—first, the pressure of the atmosphere; second, the temperature of the air; third, the hygrometrical (or moist-measured) states of the air.”
The secondary objects were:
“To compare the readings of an aneroid barometer with those of a mercurial barometer, up to five miles.
“To determine the electrical state of the air.
“To determine the oxygenic state of the atmosphere by means of ozone papers.
“To determine the time of vibration of a magnet on the earth, and at different distances from it.
“To determine the temperature of the dew point by Daniell’s dew point hygrometer and Regnault’s condensing hygrometer, and by the use of the dry and wet bulb thermometers, as ordinarily used, and their use when under the influence of the aspirator, causing considerable volumes of air to pass over both their bulbs, at different elevations, as high as possible, but particularly up to heights where man may be resident, or where troops may be located, as in the high table-lands and plains of India; with the view of ascertaining what confidence may be placed in the use of the dry and wet bulb thermometers at those elevations, by comparison with Daniell’s and Regnault’s hygrometers; and also to compare the results as found by the two hygrometers together.
“To collect air at different elevations.