A testament to the industry of the people with meagre returns.
This was around the time the land was being vested in tenants by the Land commission. Various legal changes over the previous 20 years en the tenant would have to be compensated for improvements
In contrast in England the convention was that a third of the profit from land would go to the Landlord, a third to the tenant and a third for improvements.
These are middling farms if any observer was writing about 1840 of the extraordinary efforts to reclaim even an acre from mountain to grow potatoes