153 × 1½ = 229.5 cubic feet of air per pound of carbon.

_Actual Volume_

_for One Pound Carbon_ _Per Cent_

_Cubic Feet_ _by Volume_

Carbon Dioxide 32 = 13.91 }

Oxygen 16 = 7.00 } = 20.91 per cent

Nitrogen 181.5 = 79.09

----- ------

229.5 = 100.00

For 100 per cent excess air the volume will be as follows: