Cylinders of compressed gases are often labeled to show how many "SCF" or "standard cubic feet" of gas they contain. 1 SCF of gas occupies a volume of 1 ft3 at a standard temperature and pressure of 0°C and 1 atm. A particular cylinder weighs 122 lbs when empty, and 155 lbs when filled with argon gas at 26°C. How many SCF of Ar does this cylinder contain?