Looking for something to post, I came upon the photos I had taken of a farming implement at the Thomas T. Taber Museum of the Historical Society of Williamsport, PA. We visited there at the end of October.
In a room with lots of old time stuff I saw the flail. We have one of these that we found in the barn. We never really knew what it was for until a neighbor in town described how it was used. He didn't put a name to it though.
I have no idea how old ours is but I can't imagine it was in use in the 20th century. I don't have a photo of ours and it's cold, wet and dark outside as I write this so you'll just have to believe me that ours looks just like the one hanging there. Two rods fastened together with a leather thong (I don't think ours is eel skin), with one rod shorter than the other.
I plan to print up the description and mount it next to the flail so others will now know what it is.