Page:The Fun of It.pdf/63

Rh As a rule there is a drop of about two degrees for every thousand feet. Thus on a hot summer day the temperatures about 2000 are somewhat lower than those prevailing on the ground, but often one has to go higher to be comfortable. Everyone knows that unless one encounters a breeze, the tem­perature on a mountain 5000 feet high seems little more agreeable than that at its base. In a small open plane, as contrasted with the cabin ship, one would have a pleasanter time on a summer day, and conversely more discomfort in cold weather—as in an open car. Of course, at really high altitudes regardless of season the mercury drops far below freezing.

Lieutenant Soucek, who holds the international record for altitude, encountered a temperature of 89° below.