Changing fonts (faces as they are called) is not exactly intuitive in Emacs. I set the font using the menu, but it kept reverting back to a different default font each time Emacs started.
I dont use the Toolbar, Menubar or Scrollbar in Emacs, so to access the fonts menu, hold down the Ctrl key and click the right mouse button.
Select Options > Set Font/Fontset > Misc > 9x15
In order to set the default font permanently in Emacs Initialization file, you need to know the full font name. I knew it was Misc 9x15, but Emacs complained if I put that in the .emacs file.
To find the font name, open an XTerm or Terminal and do:
xfd -fn '9x15'
An X Font Display window pops up with the font details at the top. In my case it was:
I copied the file named and added it to my .emacs file.
;; Set default font to Misc 9x15
Notice the font name is "quoted".
If there's a delay before Emacs loads file, add the following to the start of you .emacs file:
(modify-frame-parameters nil '((wait-for-wm . nil)))