Whoops! I didn't mean Thursday when I told you that the answer to last week's Whatzit would be revealed early this week.
There were two excellent guesses as to what this strange contraption might be: A clothes drier or wringer, or a paper or cardboard crimper. Both are close in their own way: This contraption is a fluting iron.
A fluting iron was used to put crimps, pleats, or ruffles into petticoats in days of yore. So it has both to do with laundry and crimping - half points to both guessers. Most fluting irons were not so fancy as this hand crank model - they usually had a ridged base and a ridged curved handheld top part. This particular fluting iron is from right here in Ellensburg, WA and is part of the oldest and most diverse collection in the museum. It's exact history is not known, but one can easily imagine the pioneer families of the Kittitas Valley ordering a fluting iron from the city to bring a little bit of luxury to their lives.
You can see many kinds of historic irons in North Dakota State University's Emily P. Reynolds Historic Costume Collection.