Found this at a yard sale but I have no idea what it is. Thoughts?

Name / What It Is

Name: Coal-Heated Washing Machine (Dutch: “Wasmachine met kolenverwarming”)
Type: Early mechanical washer with an internal heating method
Estimated period: 1925–1930
Key materials: Copper tub with a brass rim
What can be said confidently: it reflects common early 20th-century design, when home laundering relied on manual mechanics and non-electric heat.

Why It Was Made (Purpose)

Main use: Washing clothes by agitating them in hot soapy water (suds).
Problem it solved (for its time): heating wash water before reliable, powerful, and safe electric heating elements were widely available.

How It Worked

Heating the Water
- Under the tub sits a small coal stove/heater that could warm the water inside the machine.
- This was considered primitive and inefficient, but it provided a workable way to heat suds in an era of limited electric heating.
Agitation Inside the Tub
- Inside the tub is a wooden agitator (described as a “houten waskruis”—a wooden cross-shaped washing device).
- Originally, the agitator was driven by hand power using the large side wheel.
Preventing Clothes From Tangling
- To keep laundry from twisting into a tight knot, the machine used a mechanism that made the agitator move alternately left and right rather than continuously in one direction.
Later Upgrade: Electric Motor
- The description notes that an electric motor was added later, meaning the machine began as a hand-cranked washer and was modernized afterward.

Notable Features Visible in the Image

Large black flywheel on the side for manual cranking
Copper cylindrical tub with vertical ribbing and visible age/patina
Mechanical linkages above the tub that translate wheel motion to the agitator
Sturdy metal frame legs supporting the unit
Top assembly with fittings and clamps, showing an industrial, utilitarian build

Limitations and Practical Drawbacks

Inefficient heating: coal heat was slow and difficult to control precisely
Awkward workflow: stoking coal while washing in the same unit was not convenient
More labor-intensive: early operation depended on manual power until the later motor addition

Why This Machine Matters

It captures a transition period in household technology:
- From manual, mechanical washing
- To electrified convenience, as electric motors and safer heating systems became more common
The copper and brass construction also reflects the durability and material choices typical of higher-quality appliances of the era.