The screwing part is broken.
A sewing screw is used as an extra hand when embroidering or sewing edges.
The yarn is attached to the sewing screw and tightened with the other hand, now you have a free hand to sew with.
The screw is made into solid ivory and is from the late 1800's.
It is decorated with the monogram E. N. and has space for a finger bubble under the pillow.