Page:VCH Hertfordshire 1.djvu/73

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.

CLIMATE contributing to the Quarterly Weather Reports of the Registrar-General. The ' Stevenson ' screen affords a complete protection from the effects of radiation by which the thermometers under the ' Glaisher ' screen are cooled below the temperature of the air at night, and of reflection by which those in a ' Glaisher ' screen may be heated above the tempera- ture of the air on sunshiny days. The result is that while the observa- tions at Berkhamsted, St. Albans, and Bennington are strictly com- parable, the greater range of temperature shown at Royston and New Barnet is due, at least for the most part, to the exposure of the ther- mometers and not to any actual excess in the range at these two places. From experiments which have been made with the two kinds of screens it appears that it is only in the range of temperature that they give divergent results, the determination of the mean temperature not being sensibly affected. All the observations which are here utilized have been taken at 9 a.m., and entered to the day of observation, except the maximum tem- perature and the rainfall which are entered to the previous day. The regulation that the thermometers should be 4 feet above the ground and over grass has in all cases been adhered to. The position of the stations, and the names of the observers, etc., are as follows : Royston (London Road). Latitude: 52 2' 34" N. Longitude: o i' 8" W. Altitude : 301 feet. Observer : (the late) Hale Wor- tham, F.R.Met.Soc. Rain-gauge 8 inches in diameter, rim 6 inches above the ground. The observations were discontinued on the death of the observer early in the year 1899. The instruments were on the east side of, and not far from the house, the ground sloping down towards the east, and the exposure being sufficiently open. Berkbamsted (Rosebank}. Latitude: 51 45' 40" N. Longitude: o 33' 30" W. Altitude : 400 feet. Observer : Edward Mawley, Sec. R.Met.Soc. Rain-gauge 8 inches in diameter, rim i foot above the ground. The instruments are some distance from the house on ground sloping down towards the south-west, the situation being quite open. There are numerous meteorological instruments, including several which are self-recording, this being one of the most perfectly equipped meteoro- logical observatories in this country. St. Albans (The Grange}. Latitude: 51 45' 9" N. Longitude: o 20' 7" W. Altitude : 380 feet. Observer : John Hopkinson, F.R. Met.Soc. Rain-gauge 5 inches in diameter, rim i foot above the ground. Full particulars of this station, a very open situation, with a complete record of the observations from 1887 to 1896, have been given by the observer in a paper on ' The Climate of St. Albans ' in the Transactions of the Hertfordshire Natural History Society (vol. ix. pp. 215-228). The observations were discontinued here early in the year 1900 owing to the removal of the observer from St. Albans to Wat- ford. They are continued at the Hertfordshire County Museum, St. Albans, to which institution the thermometers, thermometer-screen, and 35