Since then they’ve found a system of moving the things more easily...by rocking them. It explains the peculiar shape of the base as well.
RE: ...we found a new system of rocking....
Chuck Berry song Reelin and Rockin
Well, I looked at my watch it was nine twenty one
‘Twas at a rock ‘n’ roll dance havin’ nothin’ but fun.
We were rollin’ reelin’ and a- rockin’.
We were reelin’ and a- rockin’ and rollin’ till the break of dawn