that number is a tube number, the 2 thermometers shown have a different temp. range

please show picture of complete thermometers to verify .. ... cool

the 51 thermometer reads 90 below 0, the 5 thermometer reads 60 below 0 ,

as these thermometers were used in different parts of the country ..

Last edited by advertologist; Sun Jan 21 2024 06:31 PM.
RANDY