What is "winnowings"

Usage examples of "winnowings".

So when they held the Winnowings, I was always passed over, because the Masters knew that I had been chosen in advance to be a Pilgrim.

This consisted of making a first reading of all those letters and cards of mysterious authorship and often unintelligible purpose that senior officers, for whose eyes are reserved only the least whacky winnowings, are pleased to call “communications from members of the public”.