Altitude, ft. Molar Volume, ft.3 Altitude, ft. Molar Volume, ft.3
5,000 420 50,000 2200
10,000 490 55,000 2850
15,000 590 60,000 3700
20,000 680 65,000 4900
25,000 820 70,000 6200
30,000 980 75,000 7800
35,000 1230 80,000 10,000
40,000 1410 85,000 12,600
45,000 1750 90,000 15,900
95,000 20,200
100,000 25,600
This data assumes a constant temperature (-60 $ ^{\circ} \mathrm{C} $ ) above 65,000 ft., and below that altitude is based on representative pressures and temperatures taken from Washington, Albuquerque, Pittsburgh and Lakehurst soundings.
Individual variations from season to season, and from station to station may be noted in the graphs at the left of Figures 19 and 20. These variations are at most about 10%.