Well, I looked through the appendix to the link you posted. No mention of the circumference of Antarctica. Once again, you are evidently lying.
And the link you provided is apparently just the first volume. So again, provide a source we can all check, or we know you're lying.
Here's an easier one. Can you at least provide a link to the part of "Earth Not a Globe" where Rowbotham claims Ross claimed that Antarctica has a circumference of 60,000 miles? I read through the chapter about the magnitude of the earth and couldn't find it. I mean, you're not lying about that too, are you? Surely you know where it is, since you know the book so well.