In Hodgson's Practical Uses of the Steel Square Volume 1, Mr. Hodgson quotes the instructions that came with a Sargent framing square as saying the following:

"The pitch is the proportion that the rise bears to the whole width of the building."

So a 1/3 pitch would be 8 inches of rise to a foot of run, as others have said.

Roger,

Where does Hodgson outline that screwed up version of pitch? I couldn't find it in my copy of PUOTSS.