This device is mounted on a circular stand with traces of maroon-coloured paint, on top of which is a fire with a door and four oval-shaped holes for ventilation. Inside this there is a circular alcohol heater. On top of the fire there is a brass boiler which at one side has a wheel with remains of red paint. The wheel was driven by heat from the fire and in turn drove the pulley on the other side; at the front there is a pressure gauge, an input valve for liquids and a cylindrical exhaust pipe coming out of the centre, in black and metallic gold.
A steam engine is a machine with an external combustion engine, which converts the existing heat energy into water vapour via mechanical propulsion. This piece was quite common in the Physics and Chemistry cabinets with which secondary schools were increasingly equipped above all after the application of the Moyano Education Act of 1857.