They were powered with steam originally.
Because when they were invented they were steam powered. Details (which were VERY easy to find) here:
If anythong will go wring, it will....
Are you joking? Oh my GOD - the youth of today!!!!!
I don't know - ever hear of fun answers too my dear?!!! :-D
The original steam rollers were built like locomotives and ran on steam as well as heating the roller. Today the run on petro fuel which also heats the roller.
They were among the last surviving steam-powered road vehicles, the last lingering on in service until the 1950s, possibly early 1960s, long after steam traction-engines and steam-powered lorries had been rendered commercially obsolete by the internal-combustion engine. So the term stuck, partly through metaphors. In fact their proper name was always, and still is "road roller", irrespective of their fuel.
Their survival may have been due to easy supplies of coal when the tar was a by-product of the nearest gas-works, so it was convenient to collect both fuel and material from there.
steam->hot.. hot->sexy... sexy ->sex ... sex -> hard dcik. lol.
sorry buddy, but its fun nagging you. if you feel irritated, tell me, I will stop ;)