n of these
subjects. The atmospheric pressures corresponding to various altitudes
are given in Table 12.

The weight and volume of air depend upon the pressure and the
temperature, as expressed by the formula:

Pv = 53.33 T (9)

Where P = the absolute pressure in pounds per square foot,
v = the volume in cubic feet of one pound of air,
T = the absolute temperature of the air in degrees Fahrenheit,
53.33 = a constant for air derived from the ratio of pressure, volume
and temperature of a perfect gas.

The weight of one cubic foot of air will obviously be the reciprocal of
its volume, that is, 1/v pounds.

TABLE 27

VOLUME AND WEIGHT OF AIR
AT ATMOSPHERIC PRESSURE
AT VARIOUS TEMPERATURES
_______________________________________
| | | |
| | Volume | |
| Temperature | One Pound | Weight One |
| Degrees | in | Cubic Foot |
| Fahrenheit | Cubic Feet | in Pounds |
|_____________|____________|____________|
| | | |
| 32 | 12.390 | .080710 |
| 50 | 12.843 | .077863 |
| 55 | 12.969 | .077107 |
| 60 | 13.095 | .076365 |
| 65 | 13.221 | .075637 |
| 70 | 13.347 | .074923 |
| 75 | 13.473 | .074223 |
| 80 | 13.599 | .073535 |
| 85 | 13.725 | .072860 |
| 90 | 13.851 | .072197 |
| 95 | 13.977 | .071546 |
| 100 | 14.103 | .070907 |
| 110 | 14.355 | .069662 |
| 120 | 14.607 | .068460 |
| 130 | 14.859 | .067299 |
| 140 | 15.111 | .066177 |
| 150 | 15.363 | .065092 |
| 160 | 15.615 | .064041 |
| 170 | 15.867 | .063024 |
| 180 | 16.119 | .062039 |
| 190 | 16.371 | .061084 |
| 200 | 16.623 | .060158 |
| 210 | 16.875 | .059259 |
| 212 | 16.925 | .059084 |
| 220 | 17.127 | .058388 |
| 230 | 17.379 | .057541 |
| 240 | 17.631 | .056718 |
| 250 | 17.883 | .055919 |
| 260 | 18.135 | .055142 |
| 270 | 18.387 | .054386 |
| 280 | 18.639 | .053651 |
| 290 | 18.891 | .05