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?

The choice of brass as the primary material was the first clue. Known for its durability and resistance to corrosion, brass has been a favored material in various industries, particularly in agriculture and nautical applications. The presence of numbers suggested a need for precision, perhaps in measurement or calibration.

The rotating top plate was meticulously crafted, fitting smoothly over the base. This design hinted at an adjustable function, likely related to aligning the numbers with specific markers or settings. This combination of features pointed toward a tool of some sort, yet its exact role remained elusive.

The absence of any attachment points was initially perplexing. However, this feature soon revealed itself to be a deliberate design choice. Unlike many agricultural tools that are mounted or affixed to larger equipment, this item was intended to be handheld.

In the fields, farmers often relied on portable tools that could be easily carried and used without the need for complex installation. This portability was key to its function, allowing the user to make necessary adjustments on the fly, directly in the field where conditions could vary significantly.