194 



SYMPOSIUM ON AERONAUTICS. 



Fig. 6. Mean of Wind Observations in " Highs " at looo Meters above Sea 



Level, 1907-1912. 



a direct course at the usual height or some deviation, lateral or 

 vertical, from such a coiu'se should be made. Data sufficient for 

 " laying " the course and determining beforehand the time required 

 to travel it would be furnished by the observations. The pilot would 

 to a great extent, if not altogether, be independent of having to see 

 the earth's surface in order to know his direction and position at 

 any time. 



The different convective systems or circulatory systems of the 

 atmosphere, together with the temperature distribution character- 

 izing each, are of especial interest to aeronauts. 



Fig. 3 shows a meridional section of the atmosphere, so far as it 

 can be determined from observations now at hand. For the purpose 



