J. HOPKINSON— CLIMATE OP HERTFORDSHIRE. 
125 
The five meteorological stations are Royston, Berkhamsted, 
St. Albans, Bennington, and New Barnet. They are now reduced 
to four owing to the Royston station having been discontinued 
in 1899. Observations have been taken with verified instruments 
and in an uniform manner at all these stations, but the exposure 
of the thermometers for ascertaining the temperature of the air 
iu the shade is not uniform. At Berkhamsted, St.. Albans, and 
Bennington they are in Stevenson louvre-boarded screens, in 
accordance with the regulations of the Royal Meteorological 
Society; at Royston and New Barnet under Glaisher open stands, 
as at most of the stations contributing to the “Meteorology of 
England ” in the ‘ Quarterly Reports ’ of the Registrar-General. 
Tho Stevenson screen affords a complete protection from the 
effects of radiation by which the thermometers under the Glaisher 
stand are cooled below the temperature of the air at night, and of 
reflection by which those under a Glaisher stand are heated above 
the temperature of the air on sunshiny days. While, therefore, 
the observations at Berkhamsted, St. Albans, and Bennington are 
strictly comparable, the greater range- of temperature shown at 
Royston, and the still greater at New Barnet, are features due 
rather to the difference in the exposure of the thermometers than 
to any actual excess in the range at these two places. From 
experiments which have been made between these two methods of 
exposure it appears that it is only in the range of temperature that 
they give- results which are widely divergent, the determination of 
the mean temperature not being greatly affected. 
The “Climatological Observations” which have been published 
annually in our ‘ Transactions ’ are not nearly all those which have 
been taken at these five stations. Others taken at St. Albans from 
1887 to 18-96 have been published annually, and a summary has 
been given in a paper on “The Climate of St. Albans.” * No 
further reference need, therefore, be made to these, but the means 
of some other observations taken at our two most completely 
equipped meteorological observatories, Berkhamsted and Bennington, 
which have only appeared in. our * Transactions ’ from the year 
1897, have been computed for the twelve years from the 1 Meteoro¬ 
logical Record ’ of the Royal Meteorological Society. 
All the observations which have been utilized in this communi¬ 
cation are taken at 9 a.m., but the barometrical observations at 
Berkhamsted and Bennington are also taken at 9 p.m.,, and the 
average at both hours is that here given. All are entered to the 
day of observation except the maximum temperature and the rain¬ 
fall, which are entered to the previous day. All the thermometers 
are four feet above the ground and over grass. 
The position and altitude of the various stations, with the names 
of the observers, are given in the- headings to the tables. A few 
further particulars follow.f 
Royston (London Road). —Rain-gauge 8 inches in diameter, rim 
* ‘Trans. Herts Nat. Hist. Soc.,’ vol. ix, pp. 215-228. 
t See also vol. v, pp. 203-204. 
