I can't find where I posted this unusual locomotive before, so I'll share it again, as you may not have seen it before, the Norris designed engine for the Philadelphia and Reading Railroad

Camden and Amboy railways, 1850

Jeff said it is a Crampton locomotive...the idea was to put the drive wheels behind the firebox so the builder could use larger wheels, and lower the center of gravity.

Graham said:
The locomotive's tractive effort was not sufficient for long term or heavy work. With only one driving axle and three unpowered leading axles, too much of the locomotive's weight was distributed over the unpowered lead three axles. The 6-2-0s were later rebuilt to a 4-4-0 arrangement.

Steve found that I'd posted this back in 2014