The machines used for such ascents carry, apart from the pilot, meteorologically trained observee whose duty it is to supplement information registered by the apphanoes with which the machine *s equipped by the evidence supplied by his own observations and oz: easional protographs, and who is able to co-ordinate the results of the Aights.
The ascents carried out at the flying station connected with the German Meteorological Observatory in recent months have practically always exceeded the 6,000-metre me (nearly 20,000 feet). They make it possible to study very accurately the conditions obtaining in the upper air at all states of the weather. The results that are derived from these flights are of great value, The Procedure The machine used by us is a Junkers aeroplane of the "A 20" type whose engine is capable of an output of 250 lip. The work of the pilot and the observer commences dis soon as the machine has left the round. The pilot makes exact observations of the temperature and the performance of the engine, th number of revolutions of the pro-pellet, and—with the aid of the eyroxcopie horizon fitted to the maehine—the vertical and horizons position of the latter when piercing 4 layer of clouds. Clouds are often Accompanied by heavy gusts wind, and must be approached and cleared with particular caution. It has been shown over and over again that the theory and practice of fying through clouds {Is of immense importance to the success of a fight.
At the same time the observe: jots down his notes regarding. the thickness and position of the layers of clouds, makes a careful study of their shapes and the changes in the structure, and endeavours to ¢s°- abolish the connection between th tways varying shapes of the eloul fand the currents of air due to the weather conditions. A great. dear of attention is paid to visibility in the various altitudes which froquently undergoes a rapid change in consequence of the presence of haze which, in its turn, leads to all kinds of optical phenomena.
Exerythinge noticed by the obser-wer's eyes is recorded with the aid of a pencil and a camera, at least long as he ie physically copal of doing so. When the 6,500-Line is reached and when the machine finde dificult to climb the remaining 500 metres Uefore reaching th: 7,000-metre level, because the fuel mixture in the engine becomes too thin and the temperature too cold, the two men are also greatly hampered by the conditions surrounding them.. The oxszen_content of the ravifed air is insufficient to support breathing, their limbs begin to feel as heavy as lead, end their power of obeervati
Text read from the printed page and cleaned; old type leaves the occasional error.