\hrule issue

Hi:

in plain TeX, if I do:

-------------------------------------------------------------------------------
hallo\vskip.1in

good morning

\vskip.1in hallo

\eject\end
-------------------------------------------------------------------------------

I can see as much vertical space between the first and the second line as
between the second and the tird; whereas, if I do:

-------------------------------------------------------------------------------
\hrule\vskip.1in

good morning

\vskip.1in\hrule

\eject\end
-------------------------------------------------------------------------------

I can see a large vertical space between the upper \hrule and the text but none
at all between the text and the lower \hrule.  Please help understand how to
have the same vertical space instead.

Thanks,

Rodolfo