The pumping engine at Western Springs in Auckland NZ is a compound. It actually has four cylinders and two beams, all connected to a single flywheel with a crank on each side. The HP bore and stroke are smaller than the LP, as with the engines above. Two pumps were driven, one from each beam.
The Hamilton beam engines in Hamilton Ontario are similar, except that there are two flywheels, making two separate engines with two cylinders each. Another difference is that the Hamilton engines have Watt's parallel motion where the Auckland engine has slides.
Actually once each cylinder would have been referred to as an engine, I'm not sure when that would have changed. The Hamilton engines are 1857-59, the Western Springs one was 1860's
John