I have reworked this web site to use a more modern WordPress theme (based on TwentyThirteen), rather than the archaic one.
It now looks much cleaner with more space and, importantly, adapts the layout to different screen sizes. On iPads the right hand side bar moves to the bottom to preserve the main display area and on small iPads the header image is shrunk. On iPhone-sized screens, when the top menu bar would have to become multi-line, it is replaced by a pull-down menu.
I now display a list of tags to find posts by tag.