A HISTORY OF HERTFORDSHIRE rain-gauge have been presented, with the object of securing the per- manence of the station. Bennlngton (Bennington House). Latitude : 51 53' 45" N. Longi- tude : o 5' 20" W. Altitude : 407 feet. Observer : Rev. J. D. Parker, LL.D., F.R.Met.Soc. Rain-gauge 5 inches in diameter, rim i foot above the ground. The instruments are a considerable dis- tance from the house and in a very exposed situation on the high ground overlooking a great extent of undulating country on the north and east. The situation is a very fine one and admirably adapted for showing what is the climate of the Chalk hills of the north of the county. There are numerous meteorological instruments. New Barnet (Gas Works). Latitude : 51 38' 5" N. Longitude : o 10' 15" W. Altitude: 212 feet. Observer: T. H. Martin, M.Inst.C.E. Rain-gauge 8 inches in diameter, rim i foot above the ground. The instruments are near the office of the Barnet Gas Company, apparently in a rather damp situation. Although not an ideal one for the purpose, it well represents the London Clay district on the north of London. This is the only Hertfordshire meteorological station which is not on the Chalk. There is not one of the home counties which is better supplied, for its area, with meteorological stations than is Hertfordshire, not- withstanding the discontinuance of the Royston station, and the obser- vatories are wide apart, and represent hill and valley, and chalky, gravelly, and clayey soils. Tables I. to IV. give some of the results of observations taken at these five stations during the twelve years 188710 1898. The annual means, with extremes of temperature, are given in Table I. The mean temperature of 48*3 is very little departed from at any station, Royston only showing a greater departure than 0*3. It is remarkable that this, the most northern station, should have a mean temperature o'7 higher than that of any of the other four places. There is a very close agreement between the mean minimum (or night) temperature at each station except New Barnet where it is i'9 below the mean of the other four : this is probably due in part to the kind of screen used, but chiefly to the low position and the nature of the subsoil, London Clay, which retains moisture and induces ground-fogs by which the air is rendered colder at night than it would be in a higher position and on a drier stratum. The clay is however here capped by a thin stratum of gravel. The mean maximum (or day) temperatures are in still closer agreement, the excess at Royston and New Barnet being fully accounted for by the ' Glaisher ' stand being used at these two places. This, as already mentioned, accounts for the greater range of temperature at Royston and New Barnet than at Berkhamsted, St. Albans, and Ben- nington. The only other point in this table calling for remark is the small number of rainy days registered at New Barnet owing to the omis- sion of the measurement of small falls of rain and snow, but this does not affect the amount registered. 36
