This pair of black painted knobs are from the Eastlake era. This period was during the reign of Queen Victoria of England. Dressers and chests from 1870 to 1890s often had this black wooden and brass hardware. This pair of knobs are medium size. They may have been used along with the teardrop pulls.
The knobs are one inch across and project from the drawer or door one inch. Each knob is topped with a brass cap that has the Eastlake pattern. The embedded bolt extends 1 1/4 inches from the back of the knob. It is full threaded. A square nut is included.