OT: Ding dong bell...

[Harry Bloomfield Esq]

Unusual - the deeper you go, normally the warmer it becomes..

[The Natural Philosopher]

Not in summer.

Below ground temperatures are stable at the sort of average (UK) earth temperature of around 9°C

Until you get down several hundred feet.

"In normal continental crust a typical geothermal gradient within the first 3 to 5 kilometres (2 or 3 miles) of Earth?s surface is about 25°C/km."

So a hundred meters would be at most 2.5°C and that's a *deep* well.

Most wells are less than 50 ft. far enough to be more or less isolated from surface temperature changes but shallow enough not to get any significant geothermal heating.

[Tim Lamb]

Bottom of a river valley. I don't suppose the pump was more than 5m down.

[Tim Lamb]

The real problem with *in churn* cooling was that the churns then sat out in the weather waiting for the collecting lorry.

Ours went to North London, 20 miles or so. Curious that the *unfit* returns only occurred during the summer school holiday! My mother used to use it to make soft cheese:-)

Refrigerated bulk tanks and milk tankers cured the problem.