Horizontal to vertical?

Hello,

Since you can change a vertical mill over to horizontal, is it possible
to change a horizontal over to vertical? It doesn't matter if the Z on the
head feature is sacrificed in the process since it's a knee mill. I'm
guessing no but if not it'd be really good. The machine is a Tom Senior,
here's a photo http://www.gandmtools.com/photos%20701-750/0740.html I'm
just curious because this looks a lot smaller than the other 7ft mills I'm
not allowed for my garage. : )

Thanks,
John H.