On Sun, 7 Sep 2008 at 10:32:13, Philip Eden
wrote in uk.sci.weather :

FYI, the 'external temperature' readings for the first several weeks of
Jan 1840 :

Snip

I don't know if anyone here has access to data from another English
location during this period, to see whether they sound reasonable.
--
Gives a mean for 1st-23rd of about 4.7°C. The CET for
Jan 1840 is 4.1°C, so, with an element of caution 'cos we
don't know what the rest of the month was like, they look
OK. The ranges between mild and cold spells and between day
and night look OK too.

I'll know when I get the full month's figures.

The principle of the max-min thermometer dates back to
James Six who produced them (commercially?) in the late-18th
century, though the form was rather different from those you
can buy in garden-centres today, and they were pretty
unreliable.

So nothing much has changed then...
--
Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me)