Thermometer

assuming that your explanation is demonstrable, i would take a guess that emersing the glass instrument into a hot liquid would cause an immediate reaction in the thermometer with the heat in the mercury being quickly sucked into the glass in a futile attempt to reach equilibrium (thus causing a precipitous drop in the reading) before the overall ambience of the system rises to the new average temperature considerably higher, and registering on the instument's scale. (?)

The glass being closest to the hot water expands before the mercury, making the bore larger in diameter. As the mercury warms it expands in volume by more than the bore expanded so you get a correct reading when the mercury reaches approximately the temperature it is measuring. The initial drop is less noticeable on quality thermometers that use a special glass with a low coefficient of thermal expansion. Neil

Thank you so much guys.
What would I do without your genious brains :wink: .
Take care.
I have a lot more questions I would like to post.
Once at a time