A lot of hot air

Popped round to see my aunt and uncle this morning. We had seen them briefly on Christmas Day but was in a busy and excited environment so decided to see how they were really doing :-)
My uncle was an engineer at the steel works for many decades and since his retirement (actually before his retirement) he has built and exhibited small traction engines and the like. This is a model of a ‘hero’ he has built from scratch with an explanation underneath about it