60 J. HOPKTNSON — METEOEOLOGICAl OBSEHVATIONS 



traffic both by road and rail in many parts of the country, besides 

 doing considerable damage by its violence, will be remembered 

 longer than the extremes of heat and cold ; bnt longer still by 

 far will the gale of the 14th of October, by its destruction of many 

 of our finest trees, leave its impress on the surface of the country, 

 especially in our own county so renowned for its many finely- 

 timbered parks.* 



With these exceptions the weather of the year, taken as a whole, 

 was not very different from that of 1880. The barometric pressure 

 was rather less, the mean temperature about half a degree lower, 

 and the mean daily range of temperature about the same. The 

 absolute range of temperature was more than 10° greater, and the 

 mean thermometric dryness about 1° greater (relative humidity 3 

 per cent, less), in 1881 than in 1880; and, while the total rainfall 

 was more than 4 inches less, but still considerably above the mean, 

 rain fell more frequently and snow on twice the number of days. 

 There was less cloud genei'ally, and the sky was more frequently 

 quite clear of clouds and less often completely overcast. The 

 mean force of the wind was considerably greater in 1881 than in 

 1880. In both years the most frequent direction was N.E. and 

 S.W.f 



In the following notes the general character of the weather in 

 each month, and its principal changes, are briefly referred to. 



Januaey. — Nearly 10° colder than any other month in the year, 

 as in 1880, and the coldest January I have yet registered at 

 "Watford ; with very little rain falling as rain (about half an inch), 

 but with at least an inch falling in the form of snow, and, except 

 during snowstorms, with but little wind. The first eleven days 

 were comparatively warm, the minimum tempei'ature never even 

 once falling so low as the mean of the month, but on the 12th a 

 very cold period set in and lasted to the 26th inclusive, the max. 

 temperature during this period only twice exceeding 32° and the 

 min. only twice exceeding 22°. 



The mean 9 a.m. temperature during this cold period was 20°"2, 

 giving with the above the very low mean temperature of 21°"5, the 

 mean max. being 29°-6 and the mean min. 14°*6.J During these 

 fifteen days on every one at least 5° of Irost were registered, on 

 thirteen at least 11°, on eight at least 20°, and on four at least 23°. 



* The January frost and the October gale, as experienced in Hertfordshire, 

 have been fully treated of in our ' Transactions ' by the Eev. C. W. Harvey. 

 See Vol. I, p. 228 ; and Vol. II, p. 17. 



t Not south-easterly as stated in error in the previous report, Vol. I, p. 254. 



J In all cases the mean temperature given is the mean of the 9 a.m., max., 

 and min. readings. 



