io6 Mr. George Cordeii. 



will, I trust, furnish most of the data that may be required for 

 purposes of future reference. 



Barometer. 



With regard to the mean pressure of the atmosphere, it may- 

 be observed that if it had not been for the very high readings- 

 of the barometer in the fourth quarter of the year, and 

 especially in December, when, for twenty consecutive days, 

 the mercury continued so high that no observed reading was 

 recorded lower than 30"35 ins., and on two of these days (13th 

 and 22nd) rose to the unusual height of 30'7So ins. and 

 30"8i3 ins. respectively, the annual mean would have been 

 very much lower, for I find that the mean height of the 

 barometer during the first nine months was 29-864 ins., or 

 •10 in. below the average, while the mean for the last three 

 months of the year was 30'238 ins., or -30 in. above it. The 

 exceptionally high pressures in December were accompanied 

 by dense fogs, further mention of which will be made under 

 the head of " Humidity." 



The lowest observed reading of the year was 28*864 ins., on 

 the loth of February, and the extreme range during the twelve 

 months about i'g5 ins., or nearly 2 inches. 



Temperature. 



The highest shade temperature (77 '4°) occurred on the 30th 

 of July, so that the temperature of 80° was at no time attained, 

 and even that of 70° was exceeded on only 14 days during the 

 year. The lowest shade temperature was i3"6'^ on the 7th 

 December, and, with one exception, Christmas Day, 1878, 

 lower than any previously recorded at Addiscombe. The long 

 frost, of which this low temperature was the commencement, 

 broke up very suddenly within a few days of the end of the 

 year. The number of nights on which the minimum tempera- 

 ture of the air fell below 32° was 95, but on as many as 155 

 nights the thermometer exposed on the surface of the lawn 

 fell below the freezing point, and on one of these (December 

 2nd), the exceptionally low reading of i'9° (indicating 30° of 

 frost) was registered by it. 



The temperature of the soil at a depth of one foot at no time 

 rose higher than 697°, and on one occasion (December 17th) 

 fell to within 2° of the freezing point. 

 Humidity. 



A few particulars respecting the most remarkable of the fogs 

 of the year will doubtless be of interest. The first was a wet 

 fog, unaccompanied by smoke, which lasted nearly the whole 

 day (January 17th), and by 3 p.m. had become so dense that 

 only the chimneys and the upper part of the roof of a house 75 



