VT. 



METEOROLOGICAL OBSERVATIONS TAKEX IN nERTFORDSIIIHK 



IN THE YEAR 1897. 



By Jonjf IIoPKiifsoif, F.L.S., F.G.S., F.R.Met.Soc, Assoc.Inst.C.E. 



Head at Watford, 2&th April, 1898. 



For some years three Meteorological Reports have annually been 

 communicated to the Society and printed in the ' Transactions ' — 

 (1) on the rainfall, (2) on results of climatological observations, 

 and (3) on meteorological observations at my own station, first 

 at Watford and afterwards at St. Albans. Some portions of the 

 latter have appeared in duplicate, having been included in tlie 

 climatological reports. In order to avoid this in future I have 

 determined to discontinue their publication as a separate paper, 

 giving instead, in addition to the annual report on the rainfall, 

 one general paper on meteorological observations taken chiefly at 

 five stations in Hertfordshire. 



The stations are the same as those from the records of which 

 the climatology of the county has hitherto been deduced, namely, 

 Eoyston, Bennington, Berkhamsted, St. Albans, and New Barnet ; 

 and for the sake of easy comparison with previous reports the 

 results of climatological observations are given in a series of tables 

 in the same form as before. There are also tables giving some 

 other observations taken at the two most completely equipped 

 observatories in the county, namely, Berkhamsted and Bennington. 

 The observations for these stations are taken from ' The Meteoro- 

 logical Record ' of the Royal Meteorological Society, and for 

 Royston and New Barnet from the ' Meteorology of England,' 

 which forms part of the Registrar General's ' Quarterly Report.' 



At Berkhamsted, St. Albans, and Bennington, the thermometers 

 for ascertaining the shade temperature are in Stevenson screens, 

 the observations being taken in accordance with the regulations 

 of the Royal Meteorological Society ; at Royston and New Barnet 

 they are under Glaisher screens. At Royston they have a little 

 more protection from the sun's rays than is afforded by the ordinary 

 Glaisher screen as used at New Barnet. The result of this is that 

 only the observations taken at Berkhamsted, St. Albans, and 

 Bennington can be strictly compared with each other so far as 

 regards range of temperature, the greater range shown at Royston, 

 and the still greater at New Barnet, being due to the more open 

 exposure of the thermometers, which, in the Glaisher screens, are 

 liable to be cooled below the temperature of the air by radiation at 

 night, and heated above that of the air in the daytime. The rain- 

 gauges at Royston, Berkhamsted, and New Barnet are 8 inches in 

 diameter, and those at Bennington and St. Albans are 5 inches. 



The much smaller number of days of rain at New Barnet than 

 at the other places is chiefly (if not entirely) due to the method of 



VOL. X. — PART II. 4 



