XXIX. 



THE FROST OF JANUARY, 1881, AS EXPERIENCED IN 



HERTFORDSHIRE. 



By the Rev. C. W. Haevey, M.A., F.M.S. 



Read at Hertford, 22nd March, 1881. 



Thinking sucli an exceptional frost as that which we experienced 

 in January ought not to go altogether unrecorded in our ' Trans- 

 actions,' I have collected statistics from observers in various parts 

 of our county, which I propose in the present paper to lay before 

 the Society. The stations from which, by the courtesy of 

 observers, I have received returns, well represent the county, the 

 extreme east being alone unrepresented. 



For the sake of comparison we may divide our county latitudinally 

 into three districts. (1) That which lies south of Lat. bl"^ 45', in 

 which are situated stations I-IV ; namely Moor Park, near Eick- 

 mansworth ; Southgate, near East Barnet ; Wansford House, 

 Watford ; and Nash Mills, near Hemel Hempsted. This district 

 I shall call the Southern district. 



(2) That part which lies between Lat. 51° 45' and Lat. 51° 55', 

 in which are situated stations Y-VIII ; namely Berkhampstead ; 

 Bayfordbury, near Hertford ; Rothamsted, near Harpenden ; and 

 Knebworth, near Stevenage. This I shall call the Central district. 



(3) That part which lies north of Lat. 51° 55', in which are 

 situated stations IX-XII ; namely Stevenage ; Hitchin ; Throcking, 

 near Bunting-ford ; and Boyston. Besides returns from these 

 twelve representative stations, I have retui-ns from three others, — 

 Oaklands, Watford ; Grorhambury, near St. Albans ; and Datch- 

 worth, near Welwyn ; which I have treated as supplementary 

 stations. My reason for doing this was because the locality of 

 Watford in which Oaklands is situated is sufficiently represented 

 by Moor Park and Wansford House ; and because the Gorhambury 

 and Datchworth returns are incomplete. 



In the accompanying table I have given all the information I 

 could collect, as regards the stations at which the observations 

 were taken, and the instruments used. 



In a second table I have given the daily readings of the maximum 

 and minimum thermometers at each of these stations. 



In a third table I give the mean max. and min. readings for each 

 day in each of the three districts, which will show how the cold 

 was distributed in the county. 



Finding a diversity of practice amongst observers as to the entry 

 of max. and min. temperature, some entering both to the previous 

 day, others, on the other hand, entering both to the day of observa- 

 tion, I have adapted all returns to the rule of the Meteorological 

 Society, which is, when observations are taken in the morning, to 

 enter the max. to previous day, the min. to day of ohserration. It 

 must therefore be borne in mind in examining the table that the 

 min. for 13th is the min. for the night following the 12tli day, which 

 probably occurred early on the \2>th, and so with the rest. 



