Low-High Thermometers

[Alagirl]

For those of you who managed to get one, when do you read it?

My uncle had one, almost 40 years ago, I am sure I drove him mad, as I found them highly entertaining to reset, but I had no clue how they worked or what they could possibly be for. (yes, he was a Farmer)

Now I know and covet one.

 

[Acre4Me]

What is this low-high thermometer?

 

[Alagirl]

What is this low-high thermometer?

It measures both the highest and the lowest temperature of the day.
I am sure there are electronic means these days, but sometimes I prefer the old-fashioned means.