Dear Peter

No, perhaps more like a "beak" but rather than being fixed, like a
beak, the tongue was lengthened or shortened to fill in, optically,
the word spacing.

Though your response may indicate a possible origin of the practice.
Horizontal letterform stretching is another aspect of word spacing.
This is a component of some of the TeX research I've seen, but the
amount of variance in a character is limited by its shape and to an
extremely small percentage (since it must not be visibly detected).
The attempt is to provide a refined mathematical and automatic means
of adjusting word spacing.

The variable tongue is an alternative solution. But very hard to find
any studies on, occasional reference to, etc. but that's about it.



--- In qalam@..., "Peter T. Daniels" <grammatim@...> wrote:
> Gerald Lange wrote:
> >
> > Hello members
> >
> > I'm looking for any information regarding the variegated "tongue" of a
> > letterform or character. Used for optical word spacing. Apparently
> > common in manuscript bookwork, early printed books (specifically,
> > B42), and surprisingly, some references to TeX.
> >
> > Anyone?
> >
> > Gerald Lange
> ??
> Are you maybe referring to the fact that e.g. some Hebrew letters can be
> stretched so they reach the left margin of the line?
> --
> Peter T. Daniels grammatim@...