Broadback wrote:
Can someone recommend a good min/max thermometer for my greenhouse
please? I purchased one with 2 indicators that looked like pencil lead
and a button to press to "zero" them. It was hopeless, the indicators
did not always zero and on doing so tended to bounce back up. The only
way to get it to work was subjecting to centrifugal force by wind
milling it with my arm.

http://www.ukweathershop.co.uk/acatalog/basic_sub.html lists a
stainless one, which I think is the same as the one I bought my
brother-in-law from the local garden centre.

I am surprised that no-one makes a matching pair of max-min and
Mason's (wet/dry) instruments. Never found one.