"Paul Hyett" wrote...
snip
Well, the full list of observations are : Barometer, Attached
Thermometer (attached to the barometer I assume), External
Thermometer,
Rain Gauge. For the first two, there are morning & evening readings,
and
max/min for the ext.thermometer.

When were thermometers that logged max/min temperatures invented,
anyway?

& the rain gauge location/exposure will be
problematic too.

I assume the latter *will* be located outside!

.... no doubt! But the problem comes with finding out what type of
collector is used - diameter of funnel - location relative to other
objects - representativeness to 'open ground' - was it put at ground
level (i.e. the rim *ground* level, or as for standard gauges now,
with the rim above the ground - or was it put on a roof - a common
arrangement at the time - if the latter, was the building it was put
on of a style that would significantly distort the rain 'envelope' ...
etc.
snip data
I don't know if anyone here has access to data from another English
location during this period, to see whether they sound reasonable.

.... you could plot them against the CET daily series; in fact one of
your first tasks will be to find out if Manley (or later workers)
already knew of these data and had already used these to construct the
series:-

http://hadobs.metoffice.com/hadcet/cetdl1772on.dat

There are some on the newsgroup that have had considerable experience
trying to sort these things out, so they may pitch in with advice, but
Ian Strangeways [ http://www.ianstrangeways.org.uk/ ] has written
much on the history of the development of meteorological
instrumentation (a series in 'Weather' a couple of years back), and
Stephen Burt I know has had to specifically deal with the correction
of pressure readings.

Martin.


--
Martin Rowley
West Moors, East Dorset (UK): 17m (56ft) amsl
Lat: 50.82N Long: 01.88W
NGR: SU 082 023