Missing X fonts

Like http://ubuntuforums.org/showthread.php?p=11544410, I was getting errors such as

Warning: Cannot convert string "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-*" to type FontStruct
Warning: Cannot convert string "-*-helvetica-medium-r-*--*-120-*-*-*-*-iso8859-1" to type FontStruct

(Except that I was getting the errors, not on a fresh Ubintu install, but when trying to use a fairly new machine at work, with what is probably a newer version of redHat.)

The post I quote fixed things by setting ~/.Xdefaultsto

emacs*font: 7x14

And then doing xrdb -merge ~/.Xdefaults

On my end, I found that neither 7x14 nor courier worked.  But font "fixed" did.