Most interesting of all is the steam steering apparatus which uses a small 3 cylinder radial engine driving the steering shaft via a chain drive. This engine is operated by a lever that is pulled from one side to the other to reverse the direction of motion. Unfortunately, this engine is rather all or nothing and without experience it can get on top of you!
Unfortunately, for the fortunes of the traction engine builders, modern designs like this came too late to make much of an impact on the market. The unusual features of this roller such as the steering wheel being turned right to go left and the impracticality of firing on the move made engines like this unfavorable for the roller drivers of the day. By this time, early IC engined rollers were becoming more popular, and these designs never really caught on, with the last of the traditional steam rollers carrying on into the early 1960's. A good design but about 20 years too late.
This roller can be seen at the Great Dorset Steam Fair's roller special exhibit among 100+ other steam rollers.