Continued - Part Three

It was in the upper radiator tank chamber filler tube area that created a vapor space as the water - coolant heated above the boiling point (212 degrees Fahrenheit) and began to vaporize creating a void that engineer Harrison H. Boyce recognized as a temperature sensitive zone and exploited with his namesake temperature indicating system and apparatus for automobile engines device.

Other temperature indicating gauge manufacturers would be forced to typically use the direct coolant contact temperature-indicating method that was less fore-warning or accurate.  Certain temperature indicating means/devices were comparatively much more complicated than the thermometer-based BOYCE MOTO-METER and subsequent copiers though they were extremely aesthetically pleasing while others were not very-well constructed based upon surviving examples.

At the end stages of radiator-mounted engine temperature indicating gauge era the devices became more ornamental by design or through accessorizing, in part to appeal to the growing number of actual and potential female auto owners.  Particularly French automotive mascot designers began to incorporate thermometers into their figurine designs to attract and satisfy dual accessory market interests.





The above included photos show a temperatur-indicating instrument vaulting nymph.  This type of French artisan designed indicator was intended to be practical and aesthetically pleasing.

French-made Temperature Indicator Vaulting Nymph (Front View) on
French-made Temperature Indicator Vaulting Nymph (Driver's View) on



SINCE 1912
