My CPW had a full bobbin of Jacob singles on it, and I wanted to clear it off, and ready my wheel for some flax.
I decided that I would set the singles aside for trying a "dyed THEN plied" technique.
So I reached for my reel, and started winding off. I have disconnected my "hammer" mechanism because the gears are a bit, um sticky, so I had to keep count of my turns.
This reel may be European, perhaps German in origin, and it does not measure in conventional yards. If I measure the entire distance of one pass, I wind up with about 90 inches.
Grace suggested to me that my reel could be measuring in ells. One ell is equal to 45 inches (or 1.25 yards), so one complete pass would give me the 90 inches and equal 2 ells (or 2.50 yards) I counted my turns and did the math...and wound up (or off) with approximately 392 yards...(give or take an inch or two....)and I haven't yet measured wpi.