Radiator cap with thermometer Boyce Moto Meter (0656)
Info
Old Radiator Cap with thermometer. No idea if this model was linked to a specific car. As the inscriptions are French, would have been Franch make.
On the front plate with the thermometer (seems stuck) is, the "dial" is divided in the middle with a horizontal line and there is a small through view hole. On top of the hole (high temp), there is the reading "DANGER VAPEUR" (steam :-) ). At the bottom of the hole, "MOYENNE D'ETE" (summer average).
Below the horizontal line on the left some explanation:
UN MOTEUR FROID CAUSE UNE PERTE DESSENCE
METTRE LE CHAPEAU AU RADIATEUR
(a cold engine loses petrol, put the cover on the radiator)
On the right:
UNE ELEVATION BRUQUE EST UN SIGNE DE DANGER
S'ARRETER ET EXAMINER
(a sudden rise in temperature is a sign of danger, stop and examine)
And at the bottom:
MOTEUR FROID (cold engine).
Inscriptions on the back:
BOYCE
MOTO METER
MOTO METER GES. FRANKFURT A/M