A very early eight wheel connected locomotive, actually an 0-4-0+0-4-0 central gear driven articulated. The plain tires indicate this was intended for operation on flanged rails, presumably one of the region's pre-railway era plateways. The articulated drive arrangement, to permit operation over very tight curves, further supports a plateway application. The angled cylinders, reminiscent the Stevenson's Rocket, suggest a very early date, but the need to drive the central crank could push the design into the 1840s or even later. While no dimensions are given, this is a fairly light locomotive optimized for operation over very lightly built permanent way. Probably never actually built.

Supplement to earlier comment: I am unable to confirm the track gauge as the 2'6" stated in the title. If the cylinders are actually 10.5" bore, then the driver diameter is around 4' and the track gauge close to 6'. Were there any such plateways in south Wales circa 1800-1840?