Dear MMD's,  As a Frenchman, but not being a technician, I may give
you some about what the word "cartel" signifies.

- The most common use is for a clock affixed to the wall: "Un cartel
Louis XIV, un cartel Louis XV".  By erroneous extension, "cartel de
cheminée" is sometimes used for a clock set on a mantelpiece (even if
not fixed to the wall or the mirror behind).

Some dictionaries say that cartel means "a small piece of cardboard"
("carton" in French), thus the clock dial and by extension, the clock
itself.  I have no proof of this and have doubts about the clock dial
explanation.

- Another common use is an association of some economic or political
forces: cartel de l'acier = steel trust ; cartel des gauches in 1924
and 1932 in France = association of several left-wing parties to win
the elections.

- A very specialized but widespread use in museums is to define the
small piece of printed cardboard (cartel = small card) pinned on the
wall beside a painting, or placed beside an object in a window-case to
describe it.

Now in mechanical music!  Jean-Marc Lebout has given the technical
difference between cartel and snuffbox by the respective position of
the cylinder arbor and the winding barrel.  (For more details, see the
"Dictionnaire des boîtes à musique" (in French), by Etienne Blyelle,
or Ord-Hume, "The Musical Box", p 250.)

Contrary to what has been written in a preceding posting, the word
"cartel" appears in old catalogues or documents.  See, for example,
Chapuis, "History of the Musical Box and of Mechanical Music", p. 190,
referring to a 1867 report in French :

  "A cette fabrication (NB various novelties : Nécessaires,
  porte-cigares, etc.) vint en 1833 s'ajouter celle des pièces
  de grand format dites "Cartels", qui jouent de 3 à 72 airs", etc.

 ["In this production (NB various novelties: Kits, cigar-holders,
  etc.) in 1833 were added large pieces called "Cartels", which
  played 3 to 72 songs", etc.]

Or compare the learned book by Jean-Claude Piguet, "Les faiseurs de
musiques" (de Sainte Croix), that reproduces on page 30 a funny archive
note from Sainte-Croix :

  "Trois claviers de cartels, l'un de 8 pouces 1/2 et deux de
   7 pouces ont probablement été oubliés quelque part.  On est prié
   de les rapporter chez MM Champod et Degiez, au bas du village."
   (Facsimile ? 21 juin 1856).

Which means :

  "Three cartel combs, one of 8-1/2 inches and two of 7 inches,
   have been forgotten somewhere, please take them back to MM Champod
   et Degiez, below the village."

On page 18 is shown the photograph of a clock base with the caption :
  "Un 'cartel', mouvement à musique destiné à être placé dans une
   horloge" (NB Actually in the base).

 [ "A 'cartel', musical movement intended to be put in a clock" ]

I have no time to enquire further, but it seems to me that this word
"cartel" depicted mainly the musical box movements which were placed
in clock bases during the first half of the XIXth century.

Otherwise one spoke of "pièces à musique" or "boîtes à musique"
[musical pieces or musical boxes] for large items, or "musiques" for
small movements like tabatières, novelties, etc.

I hope what I wrote is fairly exact ... and I wish you a fine spring
(the one with flowers, without barrels).

Best regards from Paris,
Philippe Rouillé
http://www.musicamecanica.org/ 

 [ At http://books.google.com/books?id=OQ8JAAAAQAAJ is the Dictionnaire
 [ de l'Académie française, Sixth edition, published in 1835, which says:
 [
 [ "Cartel also refers to the ornament that surrounds the dial of
 [  certain portable clocks made to put on the wall, on the paneling,
 [  in an apartment; and frequently the clock itself.
 [    A pretty cartel.
 [    There is in the dining room a simple cartel."
 [
 [ In the same era in the nearby Black Forest were economic cartels which
 [ controlled the manufacture and distribution of flute clocks and cuckoo
 [ clocks.  Maybe the term "cartel clock", describing the rococo Black
 [ Forest product, was also applied to the rococo French wall clock.
 [ See "Cottage Industries Business Methods", by Mark Kinsler, at
 [ http://www.mmdigest.com/Archives/Digests/200107/2001.07.23.02.html
 [
 [ -- Robbie