near the floating level on Flight 60. With a relatively slight change in elevation, the balloon passed from Westerlies (below) to Easterlies (above) with the result that the balloon was still visible from the launching site (Alamogordo, New Mexico) at sunset, $ 1 4_{2}^{\frac{1}{2}} $ hours after released. The finder reported seeing the balloon descend 35 hours after release.
Since the ballast flowing to maintain buoyancy would have been exhausted in only 5 hours, this flight provided the first evidence that such a balloon in the stratosphere maintains buoyancy much longer than at lower levels. The two factors which contribute to this are the heat added to the helium by adiabatic compression when descending and the diminished diffusion of lifting gas at a low pressure.
On Flights 56 and 60, a three-station network was set up to receive pressure signals on radio direction-finding (SCR-658) equipment. In addition, theodolites were used for several hours in each case.