Monochord?

For my birthday Karen gave me a 6 CD set, Anthology of American Folk Music, originally released in 1952 on vinyl.  Musicologist Harry Smith assembled the anthology from 78 rpm discs issued between 1927 and 1935. The boxed set comes with a lot of information in several booklets.

Anyway, my question is this. There appears to be an instrument on the album cover. Is this instrument a monochord, or am I looking at the image wrong?