TAKEN AT TnROCKING, HERTS, IN 1881. 53 



moan tomp. of 4th, 5th, and liMh on the one liand, and that of 

 7th, 8th, and 9th on tho otluT. Ivoughly speaking it was a ditl'cr- 

 ence of 2U°, namely 10° on either side of the mean. The cold 

 period was tar more remarkable, because more persistently cold, so 

 that while in 1880 the dehcieney for almost the same days was 10°, 

 this year it was as much as 18°5. 



IlviNKALL. — The driest months were April and May, the wettest, 

 I'ebruary, August, and December. The only period of anything 

 like lengthened dry weather was March 9th to April 10th, during 

 which period the only falls were "04 in. on 20th ; 01 (S) on 21st; 

 •01 (S) on 22nd, -10 on 23rd. On the other hand, the only short 

 period in which the fall was excessive was during the week ending 

 Dec. 20th, when the fall, 2-52 ins., was "44 in. in excess of the 

 mean for the whole month. 



Under the general headings of Pressure, Temperature, Rainfall, 

 and Weather, I will now add a few notes on the months, using the 

 same abi'eviations as last year, i.e. F for fog ; H hail ; L lightning ; 

 R rain ; S snow ; T thunder ; T S thunderstorm ; adding to these 

 B for bright, and C for cloudy or dull weather. 



January. — Pressure — highest 30-57 ins. on 7th ; lowest 28-82 

 ins. on 29th ; Temperature — warmest day 40°-6 on 30th, coldest 

 17°-9 on 24th; highest in sun 88°-5 on 12th; lowest on grass 3°-0 

 on 22nd. Max. above 42° on 4 days ; min. below 32° on 23 nights, 

 below 22° on 14, and below 12° on 5. The temperature between 

 13th and 26th was exceedingly low, the max. never rising above 

 32°, and the min. being below 22° with only one exception. For 

 readings of the thermometer during this period see ' Transactions,' 

 Vol. I, Part 6, p. 232. I need here only record the minima on 

 grass : — 



Minima (on grass). 



13th 14°-1 17th 6"-l 21st 5"-5 2.5th 7''-8 



14th 11 -1 18th 12 -6 22iid 3 -0 26th 9 -1 



loth 7-8 19th 21-7 23r(l 18-1 Mean 9°-9 



16th 9 -3 20th 7 -8 24th 4 -2 



Rainfall. — This would have been small but for the snowstorm of 

 the 18th, which it was impossible to gauge and difficult to estimate. 

 S 10th, 11th, 18th, 19th, 22nd. Weather— gcuGxallj B; F 9th— 

 14th, and 27th — 30th; solar halo, 17th, 3 p.m.; aurora, 31st, 

 very bright. 



Febri-ary. — Pr(?«.s?<re— highest 30-28 ins. on 21st ; lowest 28-89 

 ins. on 10th. Temperature — warmest day 44°-2 on 10th; coldest 

 27°-8 on 28th; highest in sun 100°-5 on 28th (the instrument on 

 grass out of order). Max. above 42° on 11 days; min. below 32° 

 on 16 nights. Jiainfall—S fell on 5th, 20th, 23rd, 27th, and 28th ; 

 the fall of 20th was 6 inches in depth and gauged -49 in. ; H (slight) 

 on 11th. Weather — C and wet; F prevalent 16th — 22nd; strong 

 wind 10th and 11th. 



March. — Pressure — highest 30-53 ins. on I7tli; lowest 29-09 

 ins. on 5th. Temperature — warmest day 50°-4 on 15th; coldest 

 29°-6 on 1st; highest in sun 109°-4 on 6th; lowest on grass l7°-3 



