From the article “Free Air Data in Southern California, July and August, 1913” by Dr. Wm. R. Blair, Professor of Meteorology, in the _Monthly Weather Review_, for July, 1914, it is learned that the wind shifts from west to east rather abruptly at 16 to 20 km. (10 to 12 miles); below this level down to about 5 km. (3 miles) it is quite uniformly from the west. Extremes: Maximum wind velocity 21.2 miles, 5,000 meters elevation, 5 P.M., July 24; minimum wind velocity 0.8 miles, 1,500 meters elevation, 5 P.M., July 27. The table shows a steady increase in velocity of the wind with elevation, the data being obtained from the eight meteorographs. There were four morning flights (July 31, August 3, 7, 8) and five afternoon flights (July 24, 27, August 3, 7, 8, 1913), and elevations were computed for nine heights, 1,000 to 5,000 meters. Beyond the 5,000 meters the records show that from 2 to 7 miles altitude the wind increases at approximately the same rate that the density of the air decreases.] [Illustration: CHART NO. 5 _Chart Showing Number of Flights and Duration in Hours for the Months of July to December, 1915, and January to August, 1916_ Prepared by the War Department, Signal Corps Aviation School, San Diego, California, and furnished through the courtesy of Col. W. A. Glassford, Signal Corps, U. S. Army, Commanding Officer, September 14, 1916.] [Illustration: FIG. 1. CONGRESSIONAL MEDAL AWARDED WRIGHT BROTHERS (_Designed by Morgan_) This medal was awarded Orville and Wilbur Wright by resolution of Congress, March 4, 1909. Bronze replica in possession of the writer. _Photographed May 31, 1916, by permission of the Director of the Mint, Philadelphia_] [Illustration: FIG. 2. ASCENT OF SOUNDING-BALLOONS AT AVALON _Photographed July 27, 1913_ This set was liberated from the base of the U. S. Weather Bureau, Avalon, Catalina Island, California, at 4.57 P.M., July 27, 1913, and rose to a height of 23,870 meters in one hour and three quarters when one of the balloons burst and the descent began. This was observed by Carpenter at the theodolite.] [Illustration: FIG. 3. METROGRAPH WHICH MADE THE ASCENT OF JULY 27, 1913 _Photographed August, 1913_ This meteorograph rose to a height of 23,870 meters (94,716 feet), at which height the pressure was 23 mm. (0.906 inches), temperature -52.1 C (-58 F.), relative humidity 21 per cent, wind E. (or more precisely S. 79 degrees E.), velocity 6.1 m.p.s. (14 miles per hour), but the minimum temperature was registered at 15,228 meters (49,960 feet) when the thermometer showed -64.7 C. (-85 F.), at which time the pressure was 89 mm. (3.504 inches of the barometer), relative humidity 19 per cent, wind N.W., 3.4 m.p.s. (8 miles per hour).