145 



Two instraments should always be used, and the observations at tha 

 tipper and lower station should be made and registered at the same time. The 

 temperature of the air at both stations should be also observed with care, aa the 

 mean temperature is a most important element in th« calculations. 



The nearer the two stations are together the more accurate the measure- 

 ment is likely to be. In the case of Garway we were very fortunate, the air 

 remaining perfectly stUl both at Hereford and on the Hill during the whole time 

 of our observations ; and it proved, from Mr. Roberts's levels, that we were 

 certainly not more than two feet from the truth, although the distance between 

 the upper and lower station was just 10^ miles in a straight line. 



I shall conclude this paper with some very interesting notes sent me by 

 the Rev. W. Clement Ley, of Sellack, near Ross : — " The number of days on 

 which an appreciable fall occurred at this place was a little below our yearly 

 mean. The number of days when 0"50 or upwards was registered, as also the 

 total fall for the year, considerably above it. The year was deficient here in 

 remarkable local phenomena. 



The electric display on the night of the 29th of September was the 

 grandest, as seen from here, which I have ever witnessed in England, about 

 10,000 flashes of lightning, sheet and forked, the latter of the most extraordinary 

 forms, occurring in six hours. At times from 80 to 90 electric discharges occurred 

 per minute. A S.S.E. upper current gale prevailed at the time, and the 

 electricity at the earth's surface was negative. 



The Auroral display of the 13th of May was not so brilliant here as In 

 the northern counties. That of Sept. 27th I witnessed to great advantage. I 

 observed a Ivmar rainbow at 10.40 p.m. of December 13th. 



The flood of the Wye on December 20th was as high as any which we have 

 had since February, 1853. 



Our highest temperature for the year wa« 88'.5, Aoguat 27th, and our 

 lowest (at 4 feet) 18° on the 2nd of December." 



The following are the tableg referred to :— 



