Hi, Rusty!
Yes, a cob is a male swan , too, as you say.....and apparently also a lump of coal.....
And not to mention "cobblestones".......
But there is nothing about the saying "sweating cobs" in Brewers , Bradfords, or any dictionary that I have tried - including our "new" Collins .
Googling the phrase just brings up similar thoughts to those my friend and I have already proffered!
There is no definitive movement either way!
Perhaps the expression is just open to several interpretations?
Ah well, it passed an idle moment......
Thank you for the rare book reference !
Yes, indeed worth a browse......no further word from Paper Cavalier.
Although Amazon have sent a copy of the email sent to the company.
Thank you for your contribution , Cerasus.
There seem to be quite a few possible interpretations.......but I cannot find a known (and accepted) origin of the expression.