Math Arguments

Football Puzzle

From Sam Loyd's Puzzle Encyclopedia:

We lived way back in the country and used to order our ball by mail, according to sizes advertised in a sporting house catalog, which advised patrons to "give the exact number of inches required," and that is where the problem comes in. We were told to give the size in inches, but we did not know whether it meant the number of square inches of rubber on the surface or the number of cubic inches of wind contained within  the ball so we combined  the two principles and ordered a ball which should contain just as many cubic inches of wind as it had superficial inches of surface!

How many of our puzzlists can guess the diameter of the ball which was ordered?