Great Western express enginedetails

“General Description of a Locomotive.—This is one of the Great Western express engines, running on eight wheels; the large wheel is the driving wheel, the others are called the leading and triling wheels; the chimney is seen on the right hand, the furnace on the left, and the barrel of the boiler with the tubes in the middle. Upon the top of the furnace is the steam dome and the safety valve.” (pp. 238, 240)