Picked this up at a muddy March flea market for two dollars. It has numbered notches and a rotating top plate, but no obvious way to attach it to anything. What is this thing?

rotating top plate found its way into the hands of an intrigued buyer. With no visible means of attachment, the mystery of its purpose deepened, prompting a journey into the world of agricultural history to uncover its identity.

The flea market was bustling with activity, the ground still soggy from recent rains. Among the tables laden with trinkets and oddities, one particular artifact caught the eye. It was a small object, crafted from brass, weathered by time, yet retaining a certain allure. Measuring