A monorail steam engine? No that is no joke....
It existed. The Patiala State Monorail Tramway operated from 1907 to 1927. For one of the two lines, 4 steam engines were built, the other one operated with animal carts.
Fortunately, after the lines were closed, the rolling stock was not scrapped .... it was forgotten. 35 years later, it was rediscovered and one of the little engines is actually operating in the Delhi railroad museum
http://www.youtube.com/watch?v=dpmOsCTfBoc
The monorail was built into the ordinary road. 95% of the weight was supported by the rail, only 5% on the support wheel. In contrast to an ordinary railway, track adjustment was much easier and therefore cheaper
http://www.irfca.org/members/ddickens/PSMTMain.html
