Feb 27, 2025
Roman Bronze Double-Action Water-Pump, Probably 3rd Century CE From Bolsena, Italy, The British Museum, London
This pump had two pistons (a), which were raised and lowered by a rocking-beam (b). The pistons were housed in two cylinders (c). At the bottom of each cylinder was a non-return valve (d).
When one of the pistons was raised, the valve was pushed open and the water rose inside the cylinder. When the piston reached its highest point the valve closed, trapping the water inside the cylinder.
On its downward stroke, the piston forced the water out through a side pipe (e). It then passed through a second valve (f) into the central discharge pipe (g), where it drained away.
