XX. 
METEOROLOGICAL OBSERVATIONS TAKEN AT WANSFORD 
HOUSE, WATFORD, DURING THE YEAR 1883. 
By John Hopkinson, F.L.S., F.G.S., F.R.Met.Soc. 
Read at Watford, 24 th March, 1885. 
In this, the sixth annual report of the results of meteorological 
observations taken at Wansford House, Watford, I purpose giving 
a summary, in tabular form, of some of the principal results of 
observations of the five preceding years, so that we may have a 
five-year mean with which to compare some of the features of this 
and perhaps future years; and may also obtain, as far as can he 
inferred from observations extending over such a limited period, 
more concise information on the climate of Watford than is furnished 
by the annual reports. 
During this period observations have been taken in accordance 
with the requirements of the Boyal Meteorological Society for its 
Climatological Stations, and the principal results have been 
published in that Society’s ‘ Meteorological Record.’ The pressure 
of the atmosphere, and the direction and estimated force of the 
wind, which I have recorded, are observations not required by the 
Society from these stations. 
Full particulars as to the station, the instruments used, and the 
method of observation, have been given in previous reports, but as 
reference to these reports in three different volumes of our 
1 Transactions ’ * would have to be made to ascertain these 
particulars, I will here give a summary of the information on 
these points contained in those reports. 
The longitude of the station is 0° 23' 40" W., and the latitude 
51° 39' 45" X. The position is on a slight slope towards the east, 
about half way between the highest ground in the neighbourhood 
and the alluvial plain in the valley of the Colne. The centre of 
the town of Watford is scarcely half a mile to the south. The 
ground-level, where the thermometer-screen and rain-gauge are 
placed, is 223 feet above Ordnance Datum (mean sea-level), which 
is about the average of Watford. The cistern of the barometer 
is 234 feet above this datum. 
The instruments used are by Mr. J. J. Hicks, of Hatton Garden, 
London, and (the wind-vane of course excepted) have been verified 
at the Kew Observatory. The rain-gauge has since been examined 
by Mr. G. J. Symons, F.R.S., and the barometer and thermometers 
by Mr. W. Marriott, in the course of his inspection of the 
Meteorological Society’s stations. 
The barometer is a standard on Fortin’s principle, with a tube 
half an inch in internal diameter, and requiring a correction of 
+ 0-004 inch, of which +0-003 is due to capillarity. The readings 
* ‘ Trans. Watford Nat. Hist. Soc.,’ Vol. I, p. 217, and Yol. II, p. 209; and 
‘ Trans. Herts Nat. Hist. Soc.,’ Yol. I, p. 121. 
