More about historic sail textiles
We think Nat found the correct source for Louie's statement. He didn't tell me whether it was in the Postrel or the Barber book. However, it was more talking about the difficulty of spinning with the walking wheel and indicated that it was easy to spin a loosely twisted yarn, but to do a tightly twisted one was more difficult. Therefore, the yarn was of poorer quality than when it came from a drop spindlle.
Again, thanks to all who answered my question.