368 EXTENSION OF THERMODYNAMIC COMPUTATIONS 
279 (.B = 0.002095 mm.), p = 0.01796, R = 91.20, and P = 
p R T is again exactly satisfied. These data indicate that the 
vanishing plane of the atmosphere is approaching, and a trial was 
made of z — 50,000 meters for T = 0° the approximate temper 
ature of space. Further experience with the data indicates that 
T 0° 50° 100° 150° 200° 250° 300° 
C p 0 200.00 400.00 600.00 800.00 1000.00 
Fig. 74. The dynamic data to the top of the atmosphere at 50,000 meters, 
from the balloon ascension, Huron, S. D., Sept. I, 1910 
P = Pressure in kilograms per square meter. 
— K = Radiation energy. 
p = Density in kilograms per cubic meter. 
T=Temperature in absolute degrees. 
T 1 — Temperature before the formation of the isothermal region. 
Cp = Specific heat ratio at constant pressure. 
The balloon ascension, Huron, S. D., September 1, 1910, reached the 
elevation 30,000 meters. The lines for P, — K, p, Cp, and T (up to the iso 
thermal level) converge at a point on the vanishing plane 50,000 meters. By 
a series of trials T was determined such as to make the P, — K, p curves run 
out smoothly to a common vanishing point.