I searched for "cartel" using Google.  The word appears frequently
in French, in descriptions of old pendulum clocks.

At http://mywallclock.com/wall-clock/cartel-wall-clock.htm 
  Many of these Rococo style clocks, better known today as Cartel
  clocks, were made primarily out of ormolu, or gilt bronze, although
  other rare and beautiful materials were also employed. ...

At http://www.pendulantic.com/sommaire.htm 
  La pendule française, plus volontiers appelée cartel en France ...
 [ The French pendulum clock, more cheerfully called cartel in France ...

At http://fr.wikipedia.org/wiki/Bo%C3%AEte_%C3%A0_musique 
(translated by me):
  [...]
  Two types of cylinder musical box are distinguished: the snuffbox
  type [tabatière] whose spring-barrel [barillet] is perpendicular to
  the pinned cylinder and which, as its name says, is found mainly in
  snuffboxes [tabatières]; and the cartel type whose spring-barrel is
  parallel to the pinned cylinder.  They take their name from the fact
  that in the early days they were placed in the bases of clocks called
  "cartel".  By extension, the musical movement has kept this name.

So why was the early French clock called "cartel"?

Robbie Rhodes, MMD