186 



in the possession of the Institution at that time with which 

 any trustworthy observations could be made. At the same 

 time I stated that a much better instrument had recently been 

 acquired, " a Fortin's Barometer made by Casella," with which 

 observations were commenced on the 1st of January, 1875 ; and 

 I now proceed, in the first instance, to give the results of eleven 

 years' observations, 1875-85, both years inclusive. 



It will be seen, on inspecting the accompaning tables, that the 

 mean height of the Barometer at the Bath Literary Institution 

 on an average of eleven years is 29"976 inches. This differs 

 scarcely more than three hundretlis of an inch from the result of 

 ten years' measurement at the same Institution with the old 

 instrument, spoken of in my former paper,* and set at 29-944 

 inches. It also differs but very little (only '012 inches) from the 

 mean height of the Barometer at Exeter, determined by Dr. 

 Shapter,t on an average of twelve years, to be 29 '988 inches. 

 The observations I made formerly at Swaffliam Bulbeck, in 

 Cambridgeshire, continued for nineteen years, gave a mean of 

 29'885 inches. Other observations made at the Cambridge 

 Observatory for ten years gave a result of 29"90G inches.^ 

 Combining these results we shall not be much in error, if we 

 consider the mean height of the Barometer in the southern half 

 of England as about 29-950 inches. 



In table 2 are given the greatest and lowest heights of the 

 Barometer in each month of each year from 1875 to 1885. All 

 these observations, like those in the first table, have been corrected 

 for temperature and height above the sea. On inspection they 

 will be found to possess several features of interest. 



The highest of all the Barometric observations registered is 

 30"978 inches, which occurred on January 18th, 1882. The 



* See the Club's "Proceedings," vol. iii., p. 211, 



t Climate of Sauth Devon, p. 24. 



J Observations in Meteorology, p. 139. 



